Line data Source code
1 : /*-------------------------------------------------------------------------
2 : *
3 : * deparse.c
4 : * Query deparser for postgres_fdw
5 : *
6 : * This file includes functions that examine query WHERE clauses to see
7 : * whether they're safe to send to the remote server for execution, as
8 : * well as functions to construct the query text to be sent. The latter
9 : * functionality is annoyingly duplicative of ruleutils.c, but there are
10 : * enough special considerations that it seems best to keep this separate.
11 : * One saving grace is that we only need deparse logic for node types that
12 : * we consider safe to send.
13 : *
14 : * We assume that the remote session's search_path is exactly "pg_catalog",
15 : * and thus we need schema-qualify all and only names outside pg_catalog.
16 : *
17 : * We do not consider that it is ever safe to send COLLATE expressions to
18 : * the remote server: it might not have the same collation names we do.
19 : * (Later we might consider it safe to send COLLATE "C", but even that would
20 : * fail on old remote servers.) An expression is considered safe to send
21 : * only if all operator/function input collations used in it are traceable to
22 : * Var(s) of the foreign table. That implies that if the remote server gets
23 : * a different answer than we do, the foreign table's columns are not marked
24 : * with collations that match the remote table's columns, which we can
25 : * consider to be user error.
26 : *
27 : * Portions Copyright (c) 2012-2025, PostgreSQL Global Development Group
28 : *
29 : * IDENTIFICATION
30 : * contrib/postgres_fdw/deparse.c
31 : *
32 : *-------------------------------------------------------------------------
33 : */
34 : #include "postgres.h"
35 :
36 : #include "access/htup_details.h"
37 : #include "access/sysattr.h"
38 : #include "access/table.h"
39 : #include "catalog/pg_aggregate.h"
40 : #include "catalog/pg_authid.h"
41 : #include "catalog/pg_collation.h"
42 : #include "catalog/pg_database.h"
43 : #include "catalog/pg_namespace.h"
44 : #include "catalog/pg_operator.h"
45 : #include "catalog/pg_opfamily.h"
46 : #include "catalog/pg_proc.h"
47 : #include "catalog/pg_ts_config.h"
48 : #include "catalog/pg_ts_dict.h"
49 : #include "catalog/pg_type.h"
50 : #include "commands/defrem.h"
51 : #include "nodes/nodeFuncs.h"
52 : #include "nodes/plannodes.h"
53 : #include "optimizer/optimizer.h"
54 : #include "optimizer/prep.h"
55 : #include "optimizer/tlist.h"
56 : #include "parser/parsetree.h"
57 : #include "postgres_fdw.h"
58 : #include "utils/builtins.h"
59 : #include "utils/lsyscache.h"
60 : #include "utils/rel.h"
61 : #include "utils/syscache.h"
62 : #include "utils/typcache.h"
63 :
64 : /*
65 : * Global context for foreign_expr_walker's search of an expression tree.
66 : */
67 : typedef struct foreign_glob_cxt
68 : {
69 : PlannerInfo *root; /* global planner state */
70 : RelOptInfo *foreignrel; /* the foreign relation we are planning for */
71 : Relids relids; /* relids of base relations in the underlying
72 : * scan */
73 : } foreign_glob_cxt;
74 :
75 : /*
76 : * Local (per-tree-level) context for foreign_expr_walker's search.
77 : * This is concerned with identifying collations used in the expression.
78 : */
79 : typedef enum
80 : {
81 : FDW_COLLATE_NONE, /* expression is of a noncollatable type, or
82 : * it has default collation that is not
83 : * traceable to a foreign Var */
84 : FDW_COLLATE_SAFE, /* collation derives from a foreign Var */
85 : FDW_COLLATE_UNSAFE, /* collation is non-default and derives from
86 : * something other than a foreign Var */
87 : } FDWCollateState;
88 :
89 : typedef struct foreign_loc_cxt
90 : {
91 : Oid collation; /* OID of current collation, if any */
92 : FDWCollateState state; /* state of current collation choice */
93 : } foreign_loc_cxt;
94 :
95 : /*
96 : * Context for deparseExpr
97 : */
98 : typedef struct deparse_expr_cxt
99 : {
100 : PlannerInfo *root; /* global planner state */
101 : RelOptInfo *foreignrel; /* the foreign relation we are planning for */
102 : RelOptInfo *scanrel; /* the underlying scan relation. Same as
103 : * foreignrel, when that represents a join or
104 : * a base relation. */
105 : StringInfo buf; /* output buffer to append to */
106 : List **params_list; /* exprs that will become remote Params */
107 : } deparse_expr_cxt;
108 :
109 : #define REL_ALIAS_PREFIX "r"
110 : /* Handy macro to add relation name qualification */
111 : #define ADD_REL_QUALIFIER(buf, varno) \
112 : appendStringInfo((buf), "%s%d.", REL_ALIAS_PREFIX, (varno))
113 : #define SUBQUERY_REL_ALIAS_PREFIX "s"
114 : #define SUBQUERY_COL_ALIAS_PREFIX "c"
115 :
116 : /*
117 : * Functions to determine whether an expression can be evaluated safely on
118 : * remote server.
119 : */
120 : static bool foreign_expr_walker(Node *node,
121 : foreign_glob_cxt *glob_cxt,
122 : foreign_loc_cxt *outer_cxt,
123 : foreign_loc_cxt *case_arg_cxt);
124 : static char *deparse_type_name(Oid type_oid, int32 typemod);
125 :
126 : /*
127 : * Functions to construct string representation of a node tree.
128 : */
129 : static void deparseTargetList(StringInfo buf,
130 : RangeTblEntry *rte,
131 : Index rtindex,
132 : Relation rel,
133 : bool is_returning,
134 : Bitmapset *attrs_used,
135 : bool qualify_col,
136 : List **retrieved_attrs);
137 : static void deparseExplicitTargetList(List *tlist,
138 : bool is_returning,
139 : List **retrieved_attrs,
140 : deparse_expr_cxt *context);
141 : static void deparseSubqueryTargetList(deparse_expr_cxt *context);
142 : static void deparseReturningList(StringInfo buf, RangeTblEntry *rte,
143 : Index rtindex, Relation rel,
144 : bool trig_after_row,
145 : List *withCheckOptionList,
146 : List *returningList,
147 : List **retrieved_attrs);
148 : static void deparseColumnRef(StringInfo buf, int varno, int varattno,
149 : RangeTblEntry *rte, bool qualify_col);
150 : static void deparseRelation(StringInfo buf, Relation rel);
151 : static void deparseExpr(Expr *node, deparse_expr_cxt *context);
152 : static void deparseVar(Var *node, deparse_expr_cxt *context);
153 : static void deparseConst(Const *node, deparse_expr_cxt *context, int showtype);
154 : static void deparseParam(Param *node, deparse_expr_cxt *context);
155 : static void deparseSubscriptingRef(SubscriptingRef *node, deparse_expr_cxt *context);
156 : static void deparseFuncExpr(FuncExpr *node, deparse_expr_cxt *context);
157 : static void deparseOpExpr(OpExpr *node, deparse_expr_cxt *context);
158 : static bool isPlainForeignVar(Expr *node, deparse_expr_cxt *context);
159 : static void deparseOperatorName(StringInfo buf, Form_pg_operator opform);
160 : static void deparseDistinctExpr(DistinctExpr *node, deparse_expr_cxt *context);
161 : static void deparseScalarArrayOpExpr(ScalarArrayOpExpr *node,
162 : deparse_expr_cxt *context);
163 : static void deparseRelabelType(RelabelType *node, deparse_expr_cxt *context);
164 : static void deparseBoolExpr(BoolExpr *node, deparse_expr_cxt *context);
165 : static void deparseNullTest(NullTest *node, deparse_expr_cxt *context);
166 : static void deparseCaseExpr(CaseExpr *node, deparse_expr_cxt *context);
167 : static void deparseArrayExpr(ArrayExpr *node, deparse_expr_cxt *context);
168 : static void printRemoteParam(int paramindex, Oid paramtype, int32 paramtypmod,
169 : deparse_expr_cxt *context);
170 : static void printRemotePlaceholder(Oid paramtype, int32 paramtypmod,
171 : deparse_expr_cxt *context);
172 : static void deparseSelectSql(List *tlist, bool is_subquery, List **retrieved_attrs,
173 : deparse_expr_cxt *context);
174 : static void deparseLockingClause(deparse_expr_cxt *context);
175 : static void appendOrderByClause(List *pathkeys, bool has_final_sort,
176 : deparse_expr_cxt *context);
177 : static void appendLimitClause(deparse_expr_cxt *context);
178 : static void appendConditions(List *exprs, deparse_expr_cxt *context);
179 : static void deparseFromExprForRel(StringInfo buf, PlannerInfo *root,
180 : RelOptInfo *foreignrel, bool use_alias,
181 : Index ignore_rel, List **ignore_conds,
182 : List **additional_conds,
183 : List **params_list);
184 : static void appendWhereClause(List *exprs, List *additional_conds,
185 : deparse_expr_cxt *context);
186 : static void deparseFromExpr(List *quals, deparse_expr_cxt *context);
187 : static void deparseRangeTblRef(StringInfo buf, PlannerInfo *root,
188 : RelOptInfo *foreignrel, bool make_subquery,
189 : Index ignore_rel, List **ignore_conds,
190 : List **additional_conds, List **params_list);
191 : static void deparseAggref(Aggref *node, deparse_expr_cxt *context);
192 : static void appendGroupByClause(List *tlist, deparse_expr_cxt *context);
193 : static void appendOrderBySuffix(Oid sortop, Oid sortcoltype, bool nulls_first,
194 : deparse_expr_cxt *context);
195 : static void appendAggOrderBy(List *orderList, List *targetList,
196 : deparse_expr_cxt *context);
197 : static void appendFunctionName(Oid funcid, deparse_expr_cxt *context);
198 : static Node *deparseSortGroupClause(Index ref, List *tlist, bool force_colno,
199 : deparse_expr_cxt *context);
200 :
201 : /*
202 : * Helper functions
203 : */
204 : static bool is_subquery_var(Var *node, RelOptInfo *foreignrel,
205 : int *relno, int *colno);
206 : static void get_relation_column_alias_ids(Var *node, RelOptInfo *foreignrel,
207 : int *relno, int *colno);
208 :
209 :
210 : /*
211 : * Examine each qual clause in input_conds, and classify them into two groups,
212 : * which are returned as two lists:
213 : * - remote_conds contains expressions that can be evaluated remotely
214 : * - local_conds contains expressions that can't be evaluated remotely
215 : */
216 : void
217 4904 : classifyConditions(PlannerInfo *root,
218 : RelOptInfo *baserel,
219 : List *input_conds,
220 : List **remote_conds,
221 : List **local_conds)
222 : {
223 : ListCell *lc;
224 :
225 4904 : *remote_conds = NIL;
226 4904 : *local_conds = NIL;
227 :
228 6398 : foreach(lc, input_conds)
229 : {
230 1494 : RestrictInfo *ri = lfirst_node(RestrictInfo, lc);
231 :
232 1494 : if (is_foreign_expr(root, baserel, ri->clause))
233 1328 : *remote_conds = lappend(*remote_conds, ri);
234 : else
235 166 : *local_conds = lappend(*local_conds, ri);
236 : }
237 4904 : }
238 :
239 : /*
240 : * Returns true if given expr is safe to evaluate on the foreign server.
241 : */
242 : bool
243 7516 : is_foreign_expr(PlannerInfo *root,
244 : RelOptInfo *baserel,
245 : Expr *expr)
246 : {
247 : foreign_glob_cxt glob_cxt;
248 : foreign_loc_cxt loc_cxt;
249 7516 : PgFdwRelationInfo *fpinfo = (PgFdwRelationInfo *) (baserel->fdw_private);
250 :
251 : /*
252 : * Check that the expression consists of nodes that are safe to execute
253 : * remotely.
254 : */
255 7516 : glob_cxt.root = root;
256 7516 : glob_cxt.foreignrel = baserel;
257 :
258 : /*
259 : * For an upper relation, use relids from its underneath scan relation,
260 : * because the upperrel's own relids currently aren't set to anything
261 : * meaningful by the core code. For other relation, use their own relids.
262 : */
263 7516 : if (IS_UPPER_REL(baserel))
264 906 : glob_cxt.relids = fpinfo->outerrel->relids;
265 : else
266 6610 : glob_cxt.relids = baserel->relids;
267 7516 : loc_cxt.collation = InvalidOid;
268 7516 : loc_cxt.state = FDW_COLLATE_NONE;
269 7516 : if (!foreign_expr_walker((Node *) expr, &glob_cxt, &loc_cxt, NULL))
270 300 : return false;
271 :
272 : /*
273 : * If the expression has a valid collation that does not arise from a
274 : * foreign var, the expression can not be sent over.
275 : */
276 7216 : if (loc_cxt.state == FDW_COLLATE_UNSAFE)
277 4 : return false;
278 :
279 : /*
280 : * An expression which includes any mutable functions can't be sent over
281 : * because its result is not stable. For example, sending now() remote
282 : * side could cause confusion from clock offsets. Future versions might
283 : * be able to make this choice with more granularity. (We check this last
284 : * because it requires a lot of expensive catalog lookups.)
285 : */
286 7212 : if (contain_mutable_functions((Node *) expr))
287 48 : return false;
288 :
289 : /* OK to evaluate on the remote server */
290 7164 : return true;
291 : }
292 :
293 : /*
294 : * Check if expression is safe to execute remotely, and return true if so.
295 : *
296 : * In addition, *outer_cxt is updated with collation information.
297 : *
298 : * case_arg_cxt is NULL if this subexpression is not inside a CASE-with-arg.
299 : * Otherwise, it points to the collation info derived from the arg expression,
300 : * which must be consulted by any CaseTestExpr.
301 : *
302 : * We must check that the expression contains only node types we can deparse,
303 : * that all types/functions/operators are safe to send (they are "shippable"),
304 : * and that all collations used in the expression derive from Vars of the
305 : * foreign table. Because of the latter, the logic is pretty close to
306 : * assign_collations_walker() in parse_collate.c, though we can assume here
307 : * that the given expression is valid. Note function mutability is not
308 : * currently considered here.
309 : */
310 : static bool
311 18746 : foreign_expr_walker(Node *node,
312 : foreign_glob_cxt *glob_cxt,
313 : foreign_loc_cxt *outer_cxt,
314 : foreign_loc_cxt *case_arg_cxt)
315 : {
316 18746 : bool check_type = true;
317 : PgFdwRelationInfo *fpinfo;
318 : foreign_loc_cxt inner_cxt;
319 : Oid collation;
320 : FDWCollateState state;
321 :
322 : /* Need do nothing for empty subexpressions */
323 18746 : if (node == NULL)
324 660 : return true;
325 :
326 : /* May need server info from baserel's fdw_private struct */
327 18086 : fpinfo = (PgFdwRelationInfo *) (glob_cxt->foreignrel->fdw_private);
328 :
329 : /* Set up inner_cxt for possible recursion to child nodes */
330 18086 : inner_cxt.collation = InvalidOid;
331 18086 : inner_cxt.state = FDW_COLLATE_NONE;
332 :
333 18086 : switch (nodeTag(node))
334 : {
335 8356 : case T_Var:
336 : {
337 8356 : Var *var = (Var *) node;
338 :
339 : /*
340 : * If the Var is from the foreign table, we consider its
341 : * collation (if any) safe to use. If it is from another
342 : * table, we treat its collation the same way as we would a
343 : * Param's collation, ie it's not safe for it to have a
344 : * non-default collation.
345 : */
346 8356 : if (bms_is_member(var->varno, glob_cxt->relids) &&
347 7470 : var->varlevelsup == 0)
348 : {
349 : /* Var belongs to foreign table */
350 :
351 : /*
352 : * System columns other than ctid should not be sent to
353 : * the remote, since we don't make any effort to ensure
354 : * that local and remote values match (tableoid, in
355 : * particular, almost certainly doesn't match).
356 : */
357 7470 : if (var->varattno < 0 &&
358 20 : var->varattno != SelfItemPointerAttributeNumber)
359 16 : return false;
360 :
361 : /* Else check the collation */
362 7454 : collation = var->varcollid;
363 7454 : state = OidIsValid(collation) ? FDW_COLLATE_SAFE : FDW_COLLATE_NONE;
364 : }
365 : else
366 : {
367 : /* Var belongs to some other table */
368 886 : collation = var->varcollid;
369 886 : if (collation == InvalidOid ||
370 : collation == DEFAULT_COLLATION_OID)
371 : {
372 : /*
373 : * It's noncollatable, or it's safe to combine with a
374 : * collatable foreign Var, so set state to NONE.
375 : */
376 886 : state = FDW_COLLATE_NONE;
377 : }
378 : else
379 : {
380 : /*
381 : * Do not fail right away, since the Var might appear
382 : * in a collation-insensitive context.
383 : */
384 0 : state = FDW_COLLATE_UNSAFE;
385 : }
386 : }
387 : }
388 8340 : break;
389 1854 : case T_Const:
390 : {
391 1854 : Const *c = (Const *) node;
392 :
393 : /*
394 : * Constants of regproc and related types can't be shipped
395 : * unless the referenced object is shippable. But NULL's ok.
396 : * (See also the related code in dependency.c.)
397 : */
398 1854 : if (!c->constisnull)
399 : {
400 1836 : switch (c->consttype)
401 : {
402 0 : case REGPROCOID:
403 : case REGPROCEDUREOID:
404 0 : if (!is_shippable(DatumGetObjectId(c->constvalue),
405 : ProcedureRelationId, fpinfo))
406 0 : return false;
407 0 : break;
408 0 : case REGOPEROID:
409 : case REGOPERATOROID:
410 0 : if (!is_shippable(DatumGetObjectId(c->constvalue),
411 : OperatorRelationId, fpinfo))
412 0 : return false;
413 0 : break;
414 0 : case REGCLASSOID:
415 0 : if (!is_shippable(DatumGetObjectId(c->constvalue),
416 : RelationRelationId, fpinfo))
417 0 : return false;
418 0 : break;
419 0 : case REGTYPEOID:
420 0 : if (!is_shippable(DatumGetObjectId(c->constvalue),
421 : TypeRelationId, fpinfo))
422 0 : return false;
423 0 : break;
424 0 : case REGCOLLATIONOID:
425 0 : if (!is_shippable(DatumGetObjectId(c->constvalue),
426 : CollationRelationId, fpinfo))
427 0 : return false;
428 0 : break;
429 8 : case REGCONFIGOID:
430 :
431 : /*
432 : * For text search objects only, we weaken the
433 : * normal shippability criterion to allow all OIDs
434 : * below FirstNormalObjectId. Without this, none
435 : * of the initdb-installed TS configurations would
436 : * be shippable, which would be quite annoying.
437 : */
438 8 : if (DatumGetObjectId(c->constvalue) >= FirstNormalObjectId &&
439 8 : !is_shippable(DatumGetObjectId(c->constvalue),
440 : TSConfigRelationId, fpinfo))
441 4 : return false;
442 4 : break;
443 0 : case REGDICTIONARYOID:
444 0 : if (DatumGetObjectId(c->constvalue) >= FirstNormalObjectId &&
445 0 : !is_shippable(DatumGetObjectId(c->constvalue),
446 : TSDictionaryRelationId, fpinfo))
447 0 : return false;
448 0 : break;
449 0 : case REGNAMESPACEOID:
450 0 : if (!is_shippable(DatumGetObjectId(c->constvalue),
451 : NamespaceRelationId, fpinfo))
452 0 : return false;
453 0 : break;
454 0 : case REGROLEOID:
455 0 : if (!is_shippable(DatumGetObjectId(c->constvalue),
456 : AuthIdRelationId, fpinfo))
457 0 : return false;
458 0 : break;
459 0 : case REGDATABASEOID:
460 0 : if (!is_shippable(DatumGetObjectId(c->constvalue),
461 : DatabaseRelationId, fpinfo))
462 0 : return false;
463 0 : break;
464 : }
465 : }
466 :
467 : /*
468 : * If the constant has nondefault collation, either it's of a
469 : * non-builtin type, or it reflects folding of a CollateExpr.
470 : * It's unsafe to send to the remote unless it's used in a
471 : * non-collation-sensitive context.
472 : */
473 1850 : collation = c->constcollid;
474 1850 : if (collation == InvalidOid ||
475 : collation == DEFAULT_COLLATION_OID)
476 1846 : state = FDW_COLLATE_NONE;
477 : else
478 4 : state = FDW_COLLATE_UNSAFE;
479 : }
480 1850 : break;
481 50 : case T_Param:
482 : {
483 50 : Param *p = (Param *) node;
484 :
485 : /*
486 : * If it's a MULTIEXPR Param, punt. We can't tell from here
487 : * whether the referenced sublink/subplan contains any remote
488 : * Vars; if it does, handling that is too complicated to
489 : * consider supporting at present. Fortunately, MULTIEXPR
490 : * Params are not reduced to plain PARAM_EXEC until the end of
491 : * planning, so we can easily detect this case. (Normal
492 : * PARAM_EXEC Params are safe to ship because their values
493 : * come from somewhere else in the plan tree; but a MULTIEXPR
494 : * references a sub-select elsewhere in the same targetlist,
495 : * so we'd be on the hook to evaluate it somehow if we wanted
496 : * to handle such cases as direct foreign updates.)
497 : */
498 50 : if (p->paramkind == PARAM_MULTIEXPR)
499 6 : return false;
500 :
501 : /*
502 : * Collation rule is same as for Consts and non-foreign Vars.
503 : */
504 44 : collation = p->paramcollid;
505 44 : if (collation == InvalidOid ||
506 : collation == DEFAULT_COLLATION_OID)
507 44 : state = FDW_COLLATE_NONE;
508 : else
509 0 : state = FDW_COLLATE_UNSAFE;
510 : }
511 44 : break;
512 2 : case T_SubscriptingRef:
513 : {
514 2 : SubscriptingRef *sr = (SubscriptingRef *) node;
515 :
516 : /* Assignment should not be in restrictions. */
517 2 : if (sr->refassgnexpr != NULL)
518 0 : return false;
519 :
520 : /*
521 : * Recurse into the remaining subexpressions. The container
522 : * subscripts will not affect collation of the SubscriptingRef
523 : * result, so do those first and reset inner_cxt afterwards.
524 : */
525 2 : if (!foreign_expr_walker((Node *) sr->refupperindexpr,
526 : glob_cxt, &inner_cxt, case_arg_cxt))
527 0 : return false;
528 2 : inner_cxt.collation = InvalidOid;
529 2 : inner_cxt.state = FDW_COLLATE_NONE;
530 2 : if (!foreign_expr_walker((Node *) sr->reflowerindexpr,
531 : glob_cxt, &inner_cxt, case_arg_cxt))
532 0 : return false;
533 2 : inner_cxt.collation = InvalidOid;
534 2 : inner_cxt.state = FDW_COLLATE_NONE;
535 2 : if (!foreign_expr_walker((Node *) sr->refexpr,
536 : glob_cxt, &inner_cxt, case_arg_cxt))
537 0 : return false;
538 :
539 : /*
540 : * Container subscripting typically yields same collation as
541 : * refexpr's, but in case it doesn't, use same logic as for
542 : * function nodes.
543 : */
544 2 : collation = sr->refcollid;
545 2 : if (collation == InvalidOid)
546 2 : state = FDW_COLLATE_NONE;
547 0 : else if (inner_cxt.state == FDW_COLLATE_SAFE &&
548 0 : collation == inner_cxt.collation)
549 0 : state = FDW_COLLATE_SAFE;
550 0 : else if (collation == DEFAULT_COLLATION_OID)
551 0 : state = FDW_COLLATE_NONE;
552 : else
553 0 : state = FDW_COLLATE_UNSAFE;
554 : }
555 2 : break;
556 268 : case T_FuncExpr:
557 : {
558 268 : FuncExpr *fe = (FuncExpr *) node;
559 :
560 : /*
561 : * If function used by the expression is not shippable, it
562 : * can't be sent to remote because it might have incompatible
563 : * semantics on remote side.
564 : */
565 268 : if (!is_shippable(fe->funcid, ProcedureRelationId, fpinfo))
566 16 : return false;
567 :
568 : /*
569 : * Recurse to input subexpressions.
570 : */
571 252 : if (!foreign_expr_walker((Node *) fe->args,
572 : glob_cxt, &inner_cxt, case_arg_cxt))
573 26 : return false;
574 :
575 : /*
576 : * If function's input collation is not derived from a foreign
577 : * Var, it can't be sent to remote.
578 : */
579 226 : if (fe->inputcollid == InvalidOid)
580 : /* OK, inputs are all noncollatable */ ;
581 66 : else if (inner_cxt.state != FDW_COLLATE_SAFE ||
582 40 : fe->inputcollid != inner_cxt.collation)
583 26 : return false;
584 :
585 : /*
586 : * Detect whether node is introducing a collation not derived
587 : * from a foreign Var. (If so, we just mark it unsafe for now
588 : * rather than immediately returning false, since the parent
589 : * node might not care.)
590 : */
591 200 : collation = fe->funccollid;
592 200 : if (collation == InvalidOid)
593 162 : state = FDW_COLLATE_NONE;
594 38 : else if (inner_cxt.state == FDW_COLLATE_SAFE &&
595 36 : collation == inner_cxt.collation)
596 36 : state = FDW_COLLATE_SAFE;
597 2 : else if (collation == DEFAULT_COLLATION_OID)
598 0 : state = FDW_COLLATE_NONE;
599 : else
600 2 : state = FDW_COLLATE_UNSAFE;
601 : }
602 200 : break;
603 3184 : case T_OpExpr:
604 : case T_DistinctExpr: /* struct-equivalent to OpExpr */
605 : {
606 3184 : OpExpr *oe = (OpExpr *) node;
607 :
608 : /*
609 : * Similarly, only shippable operators can be sent to remote.
610 : * (If the operator is shippable, we assume its underlying
611 : * function is too.)
612 : */
613 3184 : if (!is_shippable(oe->opno, OperatorRelationId, fpinfo))
614 94 : return false;
615 :
616 : /*
617 : * Recurse to input subexpressions.
618 : */
619 3090 : if (!foreign_expr_walker((Node *) oe->args,
620 : glob_cxt, &inner_cxt, case_arg_cxt))
621 126 : return false;
622 :
623 : /*
624 : * If operator's input collation is not derived from a foreign
625 : * Var, it can't be sent to remote.
626 : */
627 2964 : if (oe->inputcollid == InvalidOid)
628 : /* OK, inputs are all noncollatable */ ;
629 138 : else if (inner_cxt.state != FDW_COLLATE_SAFE ||
630 126 : oe->inputcollid != inner_cxt.collation)
631 12 : return false;
632 :
633 : /* Result-collation handling is same as for functions */
634 2952 : collation = oe->opcollid;
635 2952 : if (collation == InvalidOid)
636 2924 : state = FDW_COLLATE_NONE;
637 28 : else if (inner_cxt.state == FDW_COLLATE_SAFE &&
638 28 : collation == inner_cxt.collation)
639 28 : state = FDW_COLLATE_SAFE;
640 0 : else if (collation == DEFAULT_COLLATION_OID)
641 0 : state = FDW_COLLATE_NONE;
642 : else
643 0 : state = FDW_COLLATE_UNSAFE;
644 : }
645 2952 : break;
646 6 : case T_ScalarArrayOpExpr:
647 : {
648 6 : ScalarArrayOpExpr *oe = (ScalarArrayOpExpr *) node;
649 :
650 : /*
651 : * Again, only shippable operators can be sent to remote.
652 : */
653 6 : if (!is_shippable(oe->opno, OperatorRelationId, fpinfo))
654 0 : return false;
655 :
656 : /*
657 : * Recurse to input subexpressions.
658 : */
659 6 : if (!foreign_expr_walker((Node *) oe->args,
660 : glob_cxt, &inner_cxt, case_arg_cxt))
661 0 : return false;
662 :
663 : /*
664 : * If operator's input collation is not derived from a foreign
665 : * Var, it can't be sent to remote.
666 : */
667 6 : if (oe->inputcollid == InvalidOid)
668 : /* OK, inputs are all noncollatable */ ;
669 0 : else if (inner_cxt.state != FDW_COLLATE_SAFE ||
670 0 : oe->inputcollid != inner_cxt.collation)
671 0 : return false;
672 :
673 : /* Output is always boolean and so noncollatable. */
674 6 : collation = InvalidOid;
675 6 : state = FDW_COLLATE_NONE;
676 : }
677 6 : break;
678 136 : case T_RelabelType:
679 : {
680 136 : RelabelType *r = (RelabelType *) node;
681 :
682 : /*
683 : * Recurse to input subexpression.
684 : */
685 136 : if (!foreign_expr_walker((Node *) r->arg,
686 : glob_cxt, &inner_cxt, case_arg_cxt))
687 0 : return false;
688 :
689 : /*
690 : * RelabelType must not introduce a collation not derived from
691 : * an input foreign Var (same logic as for a real function).
692 : */
693 136 : collation = r->resultcollid;
694 136 : if (collation == InvalidOid)
695 0 : state = FDW_COLLATE_NONE;
696 136 : else if (inner_cxt.state == FDW_COLLATE_SAFE &&
697 128 : collation == inner_cxt.collation)
698 116 : state = FDW_COLLATE_SAFE;
699 20 : else if (collation == DEFAULT_COLLATION_OID)
700 6 : state = FDW_COLLATE_NONE;
701 : else
702 14 : state = FDW_COLLATE_UNSAFE;
703 : }
704 136 : break;
705 72 : case T_BoolExpr:
706 : {
707 72 : BoolExpr *b = (BoolExpr *) node;
708 :
709 : /*
710 : * Recurse to input subexpressions.
711 : */
712 72 : if (!foreign_expr_walker((Node *) b->args,
713 : glob_cxt, &inner_cxt, case_arg_cxt))
714 0 : return false;
715 :
716 : /* Output is always boolean and so noncollatable. */
717 72 : collation = InvalidOid;
718 72 : state = FDW_COLLATE_NONE;
719 : }
720 72 : break;
721 54 : case T_NullTest:
722 : {
723 54 : NullTest *nt = (NullTest *) node;
724 :
725 : /*
726 : * Recurse to input subexpressions.
727 : */
728 54 : if (!foreign_expr_walker((Node *) nt->arg,
729 : glob_cxt, &inner_cxt, case_arg_cxt))
730 0 : return false;
731 :
732 : /* Output is always boolean and so noncollatable. */
733 54 : collation = InvalidOid;
734 54 : state = FDW_COLLATE_NONE;
735 : }
736 54 : break;
737 26 : case T_CaseExpr:
738 : {
739 26 : CaseExpr *ce = (CaseExpr *) node;
740 : foreign_loc_cxt arg_cxt;
741 : foreign_loc_cxt tmp_cxt;
742 : ListCell *lc;
743 :
744 : /*
745 : * Recurse to CASE's arg expression, if any. Its collation
746 : * has to be saved aside for use while examining CaseTestExprs
747 : * within the WHEN expressions.
748 : */
749 26 : arg_cxt.collation = InvalidOid;
750 26 : arg_cxt.state = FDW_COLLATE_NONE;
751 26 : if (ce->arg)
752 : {
753 14 : if (!foreign_expr_walker((Node *) ce->arg,
754 : glob_cxt, &arg_cxt, case_arg_cxt))
755 2 : return false;
756 : }
757 :
758 : /* Examine the CaseWhen subexpressions. */
759 58 : foreach(lc, ce->args)
760 : {
761 34 : CaseWhen *cw = lfirst_node(CaseWhen, lc);
762 :
763 34 : if (ce->arg)
764 : {
765 : /*
766 : * In a CASE-with-arg, the parser should have produced
767 : * WHEN clauses of the form "CaseTestExpr = RHS",
768 : * possibly with an implicit coercion inserted above
769 : * the CaseTestExpr. However in an expression that's
770 : * been through the optimizer, the WHEN clause could
771 : * be almost anything (since the equality operator
772 : * could have been expanded into an inline function).
773 : * In such cases forbid pushdown, because
774 : * deparseCaseExpr can't handle it.
775 : */
776 22 : Node *whenExpr = (Node *) cw->expr;
777 : List *opArgs;
778 :
779 22 : if (!IsA(whenExpr, OpExpr))
780 2 : return false;
781 :
782 22 : opArgs = ((OpExpr *) whenExpr)->args;
783 22 : if (list_length(opArgs) != 2 ||
784 22 : !IsA(strip_implicit_coercions(linitial(opArgs)),
785 : CaseTestExpr))
786 0 : return false;
787 : }
788 :
789 : /*
790 : * Recurse to WHEN expression, passing down the arg info.
791 : * Its collation doesn't affect the result (really, it
792 : * should be boolean and thus not have a collation).
793 : */
794 34 : tmp_cxt.collation = InvalidOid;
795 34 : tmp_cxt.state = FDW_COLLATE_NONE;
796 34 : if (!foreign_expr_walker((Node *) cw->expr,
797 : glob_cxt, &tmp_cxt, &arg_cxt))
798 2 : return false;
799 :
800 : /* Recurse to THEN expression. */
801 32 : if (!foreign_expr_walker((Node *) cw->result,
802 : glob_cxt, &inner_cxt, case_arg_cxt))
803 0 : return false;
804 : }
805 :
806 : /* Recurse to ELSE expression. */
807 24 : if (!foreign_expr_walker((Node *) ce->defresult,
808 : glob_cxt, &inner_cxt, case_arg_cxt))
809 0 : return false;
810 :
811 : /*
812 : * Detect whether node is introducing a collation not derived
813 : * from a foreign Var. (If so, we just mark it unsafe for now
814 : * rather than immediately returning false, since the parent
815 : * node might not care.) This is the same as for function
816 : * nodes, except that the input collation is derived from only
817 : * the THEN and ELSE subexpressions.
818 : */
819 24 : collation = ce->casecollid;
820 24 : if (collation == InvalidOid)
821 24 : state = FDW_COLLATE_NONE;
822 0 : else if (inner_cxt.state == FDW_COLLATE_SAFE &&
823 0 : collation == inner_cxt.collation)
824 0 : state = FDW_COLLATE_SAFE;
825 0 : else if (collation == DEFAULT_COLLATION_OID)
826 0 : state = FDW_COLLATE_NONE;
827 : else
828 0 : state = FDW_COLLATE_UNSAFE;
829 : }
830 24 : break;
831 22 : case T_CaseTestExpr:
832 : {
833 22 : CaseTestExpr *c = (CaseTestExpr *) node;
834 :
835 : /* Punt if we seem not to be inside a CASE arg WHEN. */
836 22 : if (!case_arg_cxt)
837 0 : return false;
838 :
839 : /*
840 : * Otherwise, any nondefault collation attached to the
841 : * CaseTestExpr node must be derived from foreign Var(s) in
842 : * the CASE arg.
843 : */
844 22 : collation = c->collation;
845 22 : if (collation == InvalidOid)
846 16 : state = FDW_COLLATE_NONE;
847 6 : else if (case_arg_cxt->state == FDW_COLLATE_SAFE &&
848 4 : collation == case_arg_cxt->collation)
849 4 : state = FDW_COLLATE_SAFE;
850 2 : else if (collation == DEFAULT_COLLATION_OID)
851 0 : state = FDW_COLLATE_NONE;
852 : else
853 2 : state = FDW_COLLATE_UNSAFE;
854 : }
855 22 : break;
856 8 : case T_ArrayExpr:
857 : {
858 8 : ArrayExpr *a = (ArrayExpr *) node;
859 :
860 : /*
861 : * Recurse to input subexpressions.
862 : */
863 8 : if (!foreign_expr_walker((Node *) a->elements,
864 : glob_cxt, &inner_cxt, case_arg_cxt))
865 0 : return false;
866 :
867 : /*
868 : * ArrayExpr must not introduce a collation not derived from
869 : * an input foreign Var (same logic as for a function).
870 : */
871 8 : collation = a->array_collid;
872 8 : if (collation == InvalidOid)
873 8 : state = FDW_COLLATE_NONE;
874 0 : else if (inner_cxt.state == FDW_COLLATE_SAFE &&
875 0 : collation == inner_cxt.collation)
876 0 : state = FDW_COLLATE_SAFE;
877 0 : else if (collation == DEFAULT_COLLATION_OID)
878 0 : state = FDW_COLLATE_NONE;
879 : else
880 0 : state = FDW_COLLATE_UNSAFE;
881 : }
882 8 : break;
883 3428 : case T_List:
884 : {
885 3428 : List *l = (List *) node;
886 : ListCell *lc;
887 :
888 : /*
889 : * Recurse to component subexpressions.
890 : */
891 9764 : foreach(lc, l)
892 : {
893 6514 : if (!foreign_expr_walker((Node *) lfirst(lc),
894 : glob_cxt, &inner_cxt, case_arg_cxt))
895 178 : return false;
896 : }
897 :
898 : /*
899 : * When processing a list, collation state just bubbles up
900 : * from the list elements.
901 : */
902 3250 : collation = inner_cxt.collation;
903 3250 : state = inner_cxt.state;
904 :
905 : /* Don't apply exprType() to the list. */
906 3250 : check_type = false;
907 : }
908 3250 : break;
909 560 : case T_Aggref:
910 : {
911 560 : Aggref *agg = (Aggref *) node;
912 : ListCell *lc;
913 :
914 : /* Not safe to pushdown when not in grouping context */
915 560 : if (!IS_UPPER_REL(glob_cxt->foreignrel))
916 0 : return false;
917 :
918 : /* Only non-split aggregates are pushable. */
919 560 : if (agg->aggsplit != AGGSPLIT_SIMPLE)
920 0 : return false;
921 :
922 : /* As usual, it must be shippable. */
923 560 : if (!is_shippable(agg->aggfnoid, ProcedureRelationId, fpinfo))
924 8 : return false;
925 :
926 : /*
927 : * Recurse to input args. aggdirectargs, aggorder and
928 : * aggdistinct are all present in args, so no need to check
929 : * their shippability explicitly.
930 : */
931 996 : foreach(lc, agg->args)
932 : {
933 468 : Node *n = (Node *) lfirst(lc);
934 :
935 : /* If TargetEntry, extract the expression from it */
936 468 : if (IsA(n, TargetEntry))
937 : {
938 468 : TargetEntry *tle = (TargetEntry *) n;
939 :
940 468 : n = (Node *) tle->expr;
941 : }
942 :
943 468 : if (!foreign_expr_walker(n,
944 : glob_cxt, &inner_cxt, case_arg_cxt))
945 24 : return false;
946 : }
947 :
948 : /*
949 : * For aggorder elements, check whether the sort operator, if
950 : * specified, is shippable or not.
951 : */
952 528 : if (agg->aggorder)
953 : {
954 140 : foreach(lc, agg->aggorder)
955 : {
956 76 : SortGroupClause *srt = (SortGroupClause *) lfirst(lc);
957 : Oid sortcoltype;
958 : TypeCacheEntry *typentry;
959 : TargetEntry *tle;
960 :
961 76 : tle = get_sortgroupref_tle(srt->tleSortGroupRef,
962 : agg->args);
963 76 : sortcoltype = exprType((Node *) tle->expr);
964 76 : typentry = lookup_type_cache(sortcoltype,
965 : TYPECACHE_LT_OPR | TYPECACHE_GT_OPR);
966 : /* Check shippability of non-default sort operator. */
967 76 : if (srt->sortop != typentry->lt_opr &&
968 28 : srt->sortop != typentry->gt_opr &&
969 12 : !is_shippable(srt->sortop, OperatorRelationId,
970 : fpinfo))
971 8 : return false;
972 : }
973 : }
974 :
975 : /* Check aggregate filter */
976 520 : if (!foreign_expr_walker((Node *) agg->aggfilter,
977 : glob_cxt, &inner_cxt, case_arg_cxt))
978 4 : return false;
979 :
980 : /*
981 : * If aggregate's input collation is not derived from a
982 : * foreign Var, it can't be sent to remote.
983 : */
984 516 : if (agg->inputcollid == InvalidOid)
985 : /* OK, inputs are all noncollatable */ ;
986 44 : else if (inner_cxt.state != FDW_COLLATE_SAFE ||
987 44 : agg->inputcollid != inner_cxt.collation)
988 0 : return false;
989 :
990 : /*
991 : * Detect whether node is introducing a collation not derived
992 : * from a foreign Var. (If so, we just mark it unsafe for now
993 : * rather than immediately returning false, since the parent
994 : * node might not care.)
995 : */
996 516 : collation = agg->aggcollid;
997 516 : if (collation == InvalidOid)
998 514 : state = FDW_COLLATE_NONE;
999 2 : else if (inner_cxt.state == FDW_COLLATE_SAFE &&
1000 2 : collation == inner_cxt.collation)
1001 2 : state = FDW_COLLATE_SAFE;
1002 0 : else if (collation == DEFAULT_COLLATION_OID)
1003 0 : state = FDW_COLLATE_NONE;
1004 : else
1005 0 : state = FDW_COLLATE_UNSAFE;
1006 : }
1007 516 : break;
1008 60 : default:
1009 :
1010 : /*
1011 : * If it's anything else, assume it's unsafe. This list can be
1012 : * expanded later, but don't forget to add deparse support below.
1013 : */
1014 60 : return false;
1015 : }
1016 :
1017 : /*
1018 : * If result type of given expression is not shippable, it can't be sent
1019 : * to remote because it might have incompatible semantics on remote side.
1020 : */
1021 17476 : if (check_type && !is_shippable(exprType(node), TypeRelationId, fpinfo))
1022 50 : return false;
1023 :
1024 : /*
1025 : * Now, merge my collation information into my parent's state.
1026 : */
1027 17426 : if (state > outer_cxt->state)
1028 : {
1029 : /* Override previous parent state */
1030 960 : outer_cxt->collation = collation;
1031 960 : outer_cxt->state = state;
1032 : }
1033 16466 : else if (state == outer_cxt->state)
1034 : {
1035 : /* Merge, or detect error if there's a collation conflict */
1036 16364 : switch (state)
1037 : {
1038 16340 : case FDW_COLLATE_NONE:
1039 : /* Nothing + nothing is still nothing */
1040 16340 : break;
1041 22 : case FDW_COLLATE_SAFE:
1042 22 : if (collation != outer_cxt->collation)
1043 : {
1044 : /*
1045 : * Non-default collation always beats default.
1046 : */
1047 0 : if (outer_cxt->collation == DEFAULT_COLLATION_OID)
1048 : {
1049 : /* Override previous parent state */
1050 0 : outer_cxt->collation = collation;
1051 : }
1052 0 : else if (collation != DEFAULT_COLLATION_OID)
1053 : {
1054 : /*
1055 : * Conflict; show state as indeterminate. We don't
1056 : * want to "return false" right away, since parent
1057 : * node might not care about collation.
1058 : */
1059 0 : outer_cxt->state = FDW_COLLATE_UNSAFE;
1060 : }
1061 : }
1062 22 : break;
1063 2 : case FDW_COLLATE_UNSAFE:
1064 : /* We're still conflicted ... */
1065 2 : break;
1066 : }
1067 : }
1068 :
1069 : /* It looks OK */
1070 17426 : return true;
1071 : }
1072 :
1073 : /*
1074 : * Returns true if given expr is something we'd have to send the value of
1075 : * to the foreign server.
1076 : *
1077 : * This should return true when the expression is a shippable node that
1078 : * deparseExpr would add to context->params_list. Note that we don't care
1079 : * if the expression *contains* such a node, only whether one appears at top
1080 : * level. We need this to detect cases where setrefs.c would recognize a
1081 : * false match between an fdw_exprs item (which came from the params_list)
1082 : * and an entry in fdw_scan_tlist (which we're considering putting the given
1083 : * expression into).
1084 : */
1085 : bool
1086 552 : is_foreign_param(PlannerInfo *root,
1087 : RelOptInfo *baserel,
1088 : Expr *expr)
1089 : {
1090 552 : if (expr == NULL)
1091 0 : return false;
1092 :
1093 552 : switch (nodeTag(expr))
1094 : {
1095 152 : case T_Var:
1096 : {
1097 : /* It would have to be sent unless it's a foreign Var */
1098 152 : Var *var = (Var *) expr;
1099 152 : PgFdwRelationInfo *fpinfo = (PgFdwRelationInfo *) (baserel->fdw_private);
1100 : Relids relids;
1101 :
1102 152 : if (IS_UPPER_REL(baserel))
1103 152 : relids = fpinfo->outerrel->relids;
1104 : else
1105 0 : relids = baserel->relids;
1106 :
1107 152 : if (bms_is_member(var->varno, relids) && var->varlevelsup == 0)
1108 152 : return false; /* foreign Var, so not a param */
1109 : else
1110 0 : return true; /* it'd have to be a param */
1111 : break;
1112 : }
1113 8 : case T_Param:
1114 : /* Params always have to be sent to the foreign server */
1115 8 : return true;
1116 392 : default:
1117 392 : break;
1118 : }
1119 392 : return false;
1120 : }
1121 :
1122 : /*
1123 : * Returns true if it's safe to push down the sort expression described by
1124 : * 'pathkey' to the foreign server.
1125 : */
1126 : bool
1127 1550 : is_foreign_pathkey(PlannerInfo *root,
1128 : RelOptInfo *baserel,
1129 : PathKey *pathkey)
1130 : {
1131 1550 : EquivalenceClass *pathkey_ec = pathkey->pk_eclass;
1132 1550 : PgFdwRelationInfo *fpinfo = (PgFdwRelationInfo *) baserel->fdw_private;
1133 :
1134 : /*
1135 : * is_foreign_expr would detect volatile expressions as well, but checking
1136 : * ec_has_volatile here saves some cycles.
1137 : */
1138 1550 : if (pathkey_ec->ec_has_volatile)
1139 8 : return false;
1140 :
1141 : /* can't push down the sort if the pathkey's opfamily is not shippable */
1142 1542 : if (!is_shippable(pathkey->pk_opfamily, OperatorFamilyRelationId, fpinfo))
1143 6 : return false;
1144 :
1145 : /* can push if a suitable EC member exists */
1146 1536 : return (find_em_for_rel(root, pathkey_ec, baserel) != NULL);
1147 : }
1148 :
1149 : /*
1150 : * Convert type OID + typmod info into a type name we can ship to the remote
1151 : * server. Someplace else had better have verified that this type name is
1152 : * expected to be known on the remote end.
1153 : *
1154 : * This is almost just format_type_with_typemod(), except that if left to its
1155 : * own devices, that function will make schema-qualification decisions based
1156 : * on the local search_path, which is wrong. We must schema-qualify all
1157 : * type names that are not in pg_catalog. We assume here that built-in types
1158 : * are all in pg_catalog and need not be qualified; otherwise, qualify.
1159 : */
1160 : static char *
1161 1084 : deparse_type_name(Oid type_oid, int32 typemod)
1162 : {
1163 1084 : bits16 flags = FORMAT_TYPE_TYPEMOD_GIVEN;
1164 :
1165 1084 : if (!is_builtin(type_oid))
1166 0 : flags |= FORMAT_TYPE_FORCE_QUALIFY;
1167 :
1168 1084 : return format_type_extended(type_oid, typemod, flags);
1169 : }
1170 :
1171 : /*
1172 : * Build the targetlist for given relation to be deparsed as SELECT clause.
1173 : *
1174 : * The output targetlist contains the columns that need to be fetched from the
1175 : * foreign server for the given relation. If foreignrel is an upper relation,
1176 : * then the output targetlist can also contain expressions to be evaluated on
1177 : * foreign server.
1178 : */
1179 : List *
1180 1602 : build_tlist_to_deparse(RelOptInfo *foreignrel)
1181 : {
1182 1602 : List *tlist = NIL;
1183 1602 : PgFdwRelationInfo *fpinfo = (PgFdwRelationInfo *) foreignrel->fdw_private;
1184 : ListCell *lc;
1185 :
1186 : /*
1187 : * For an upper relation, we have already built the target list while
1188 : * checking shippability, so just return that.
1189 : */
1190 1602 : if (IS_UPPER_REL(foreignrel))
1191 330 : return fpinfo->grouped_tlist;
1192 :
1193 : /*
1194 : * We require columns specified in foreignrel->reltarget->exprs and those
1195 : * required for evaluating the local conditions.
1196 : */
1197 1272 : tlist = add_to_flat_tlist(tlist,
1198 1272 : pull_var_clause((Node *) foreignrel->reltarget->exprs,
1199 : PVC_RECURSE_PLACEHOLDERS));
1200 1320 : foreach(lc, fpinfo->local_conds)
1201 : {
1202 48 : RestrictInfo *rinfo = lfirst_node(RestrictInfo, lc);
1203 :
1204 48 : tlist = add_to_flat_tlist(tlist,
1205 48 : pull_var_clause((Node *) rinfo->clause,
1206 : PVC_RECURSE_PLACEHOLDERS));
1207 : }
1208 :
1209 1272 : return tlist;
1210 : }
1211 :
1212 : /*
1213 : * Deparse SELECT statement for given relation into buf.
1214 : *
1215 : * tlist contains the list of desired columns to be fetched from foreign server.
1216 : * For a base relation fpinfo->attrs_used is used to construct SELECT clause,
1217 : * hence the tlist is ignored for a base relation.
1218 : *
1219 : * remote_conds is the list of conditions to be deparsed into the WHERE clause
1220 : * (or, in the case of upper relations, into the HAVING clause).
1221 : *
1222 : * If params_list is not NULL, it receives a list of Params and other-relation
1223 : * Vars used in the clauses; these values must be transmitted to the remote
1224 : * server as parameter values.
1225 : *
1226 : * If params_list is NULL, we're generating the query for EXPLAIN purposes,
1227 : * so Params and other-relation Vars should be replaced by dummy values.
1228 : *
1229 : * pathkeys is the list of pathkeys to order the result by.
1230 : *
1231 : * is_subquery is the flag to indicate whether to deparse the specified
1232 : * relation as a subquery.
1233 : *
1234 : * List of columns selected is returned in retrieved_attrs.
1235 : */
1236 : void
1237 4632 : deparseSelectStmtForRel(StringInfo buf, PlannerInfo *root, RelOptInfo *rel,
1238 : List *tlist, List *remote_conds, List *pathkeys,
1239 : bool has_final_sort, bool has_limit, bool is_subquery,
1240 : List **retrieved_attrs, List **params_list)
1241 : {
1242 : deparse_expr_cxt context;
1243 4632 : PgFdwRelationInfo *fpinfo = (PgFdwRelationInfo *) rel->fdw_private;
1244 : List *quals;
1245 :
1246 : /*
1247 : * We handle relations for foreign tables, joins between those and upper
1248 : * relations.
1249 : */
1250 : Assert(IS_JOIN_REL(rel) || IS_SIMPLE_REL(rel) || IS_UPPER_REL(rel));
1251 :
1252 : /* Fill portions of context common to upper, join and base relation */
1253 4632 : context.buf = buf;
1254 4632 : context.root = root;
1255 4632 : context.foreignrel = rel;
1256 4632 : context.scanrel = IS_UPPER_REL(rel) ? fpinfo->outerrel : rel;
1257 4632 : context.params_list = params_list;
1258 :
1259 : /* Construct SELECT clause */
1260 4632 : deparseSelectSql(tlist, is_subquery, retrieved_attrs, &context);
1261 :
1262 : /*
1263 : * For upper relations, the WHERE clause is built from the remote
1264 : * conditions of the underlying scan relation; otherwise, we can use the
1265 : * supplied list of remote conditions directly.
1266 : */
1267 4632 : if (IS_UPPER_REL(rel))
1268 330 : {
1269 : PgFdwRelationInfo *ofpinfo;
1270 :
1271 330 : ofpinfo = (PgFdwRelationInfo *) fpinfo->outerrel->fdw_private;
1272 330 : quals = ofpinfo->remote_conds;
1273 : }
1274 : else
1275 4302 : quals = remote_conds;
1276 :
1277 : /* Construct FROM and WHERE clauses */
1278 4632 : deparseFromExpr(quals, &context);
1279 :
1280 4632 : if (IS_UPPER_REL(rel))
1281 : {
1282 : /* Append GROUP BY clause */
1283 330 : appendGroupByClause(tlist, &context);
1284 :
1285 : /* Append HAVING clause */
1286 330 : if (remote_conds)
1287 : {
1288 36 : appendStringInfoString(buf, " HAVING ");
1289 36 : appendConditions(remote_conds, &context);
1290 : }
1291 : }
1292 :
1293 : /* Add ORDER BY clause if we found any useful pathkeys */
1294 4632 : if (pathkeys)
1295 1474 : appendOrderByClause(pathkeys, has_final_sort, &context);
1296 :
1297 : /* Add LIMIT clause if necessary */
1298 4632 : if (has_limit)
1299 292 : appendLimitClause(&context);
1300 :
1301 : /* Add any necessary FOR UPDATE/SHARE. */
1302 4632 : deparseLockingClause(&context);
1303 4632 : }
1304 :
1305 : /*
1306 : * Construct a simple SELECT statement that retrieves desired columns
1307 : * of the specified foreign table, and append it to "buf". The output
1308 : * contains just "SELECT ... ".
1309 : *
1310 : * We also create an integer List of the columns being retrieved, which is
1311 : * returned to *retrieved_attrs, unless we deparse the specified relation
1312 : * as a subquery.
1313 : *
1314 : * tlist is the list of desired columns. is_subquery is the flag to
1315 : * indicate whether to deparse the specified relation as a subquery.
1316 : * Read prologue of deparseSelectStmtForRel() for details.
1317 : */
1318 : static void
1319 4632 : deparseSelectSql(List *tlist, bool is_subquery, List **retrieved_attrs,
1320 : deparse_expr_cxt *context)
1321 : {
1322 4632 : StringInfo buf = context->buf;
1323 4632 : RelOptInfo *foreignrel = context->foreignrel;
1324 4632 : PlannerInfo *root = context->root;
1325 4632 : PgFdwRelationInfo *fpinfo = (PgFdwRelationInfo *) foreignrel->fdw_private;
1326 :
1327 : /*
1328 : * Construct SELECT list
1329 : */
1330 4632 : appendStringInfoString(buf, "SELECT ");
1331 :
1332 4632 : if (is_subquery)
1333 : {
1334 : /*
1335 : * For a relation that is deparsed as a subquery, emit expressions
1336 : * specified in the relation's reltarget. Note that since this is for
1337 : * the subquery, no need to care about *retrieved_attrs.
1338 : */
1339 100 : deparseSubqueryTargetList(context);
1340 : }
1341 4532 : else if (IS_JOIN_REL(foreignrel) || IS_UPPER_REL(foreignrel))
1342 : {
1343 : /*
1344 : * For a join or upper relation the input tlist gives the list of
1345 : * columns required to be fetched from the foreign server.
1346 : */
1347 1602 : deparseExplicitTargetList(tlist, false, retrieved_attrs, context);
1348 : }
1349 : else
1350 : {
1351 : /*
1352 : * For a base relation fpinfo->attrs_used gives the list of columns
1353 : * required to be fetched from the foreign server.
1354 : */
1355 2930 : RangeTblEntry *rte = planner_rt_fetch(foreignrel->relid, root);
1356 :
1357 : /*
1358 : * Core code already has some lock on each rel being planned, so we
1359 : * can use NoLock here.
1360 : */
1361 2930 : Relation rel = table_open(rte->relid, NoLock);
1362 :
1363 2930 : deparseTargetList(buf, rte, foreignrel->relid, rel, false,
1364 : fpinfo->attrs_used, false, retrieved_attrs);
1365 2930 : table_close(rel, NoLock);
1366 : }
1367 4632 : }
1368 :
1369 : /*
1370 : * Construct a FROM clause and, if needed, a WHERE clause, and append those to
1371 : * "buf".
1372 : *
1373 : * quals is the list of clauses to be included in the WHERE clause.
1374 : * (These may or may not include RestrictInfo decoration.)
1375 : */
1376 : static void
1377 4632 : deparseFromExpr(List *quals, deparse_expr_cxt *context)
1378 : {
1379 4632 : StringInfo buf = context->buf;
1380 4632 : RelOptInfo *scanrel = context->scanrel;
1381 4632 : List *additional_conds = NIL;
1382 :
1383 : /* For upper relations, scanrel must be either a joinrel or a baserel */
1384 : Assert(!IS_UPPER_REL(context->foreignrel) ||
1385 : IS_JOIN_REL(scanrel) || IS_SIMPLE_REL(scanrel));
1386 :
1387 : /* Construct FROM clause */
1388 4632 : appendStringInfoString(buf, " FROM ");
1389 4632 : deparseFromExprForRel(buf, context->root, scanrel,
1390 4632 : (bms_membership(scanrel->relids) == BMS_MULTIPLE),
1391 : (Index) 0, NULL, &additional_conds,
1392 : context->params_list);
1393 4632 : appendWhereClause(quals, additional_conds, context);
1394 4632 : if (additional_conds != NIL)
1395 316 : list_free_deep(additional_conds);
1396 4632 : }
1397 :
1398 : /*
1399 : * Emit a target list that retrieves the columns specified in attrs_used.
1400 : * This is used for both SELECT and RETURNING targetlists; the is_returning
1401 : * parameter is true only for a RETURNING targetlist.
1402 : *
1403 : * The tlist text is appended to buf, and we also create an integer List
1404 : * of the columns being retrieved, which is returned to *retrieved_attrs.
1405 : *
1406 : * If qualify_col is true, add relation alias before the column name.
1407 : */
1408 : static void
1409 3698 : deparseTargetList(StringInfo buf,
1410 : RangeTblEntry *rte,
1411 : Index rtindex,
1412 : Relation rel,
1413 : bool is_returning,
1414 : Bitmapset *attrs_used,
1415 : bool qualify_col,
1416 : List **retrieved_attrs)
1417 : {
1418 3698 : TupleDesc tupdesc = RelationGetDescr(rel);
1419 : bool have_wholerow;
1420 : bool first;
1421 : int i;
1422 :
1423 3698 : *retrieved_attrs = NIL;
1424 :
1425 : /* If there's a whole-row reference, we'll need all the columns. */
1426 3698 : have_wholerow = bms_is_member(0 - FirstLowInvalidHeapAttributeNumber,
1427 : attrs_used);
1428 :
1429 3698 : first = true;
1430 26682 : for (i = 1; i <= tupdesc->natts; i++)
1431 : {
1432 22984 : Form_pg_attribute attr = TupleDescAttr(tupdesc, i - 1);
1433 :
1434 : /* Ignore dropped attributes. */
1435 22984 : if (attr->attisdropped)
1436 2072 : continue;
1437 :
1438 35016 : if (have_wholerow ||
1439 14104 : bms_is_member(i - FirstLowInvalidHeapAttributeNumber,
1440 : attrs_used))
1441 : {
1442 13030 : if (!first)
1443 9574 : appendStringInfoString(buf, ", ");
1444 3456 : else if (is_returning)
1445 224 : appendStringInfoString(buf, " RETURNING ");
1446 13030 : first = false;
1447 :
1448 13030 : deparseColumnRef(buf, rtindex, i, rte, qualify_col);
1449 :
1450 13030 : *retrieved_attrs = lappend_int(*retrieved_attrs, i);
1451 : }
1452 : }
1453 :
1454 : /*
1455 : * Add ctid if needed. We currently don't support retrieving any other
1456 : * system columns.
1457 : */
1458 3698 : if (bms_is_member(SelfItemPointerAttributeNumber - FirstLowInvalidHeapAttributeNumber,
1459 : attrs_used))
1460 : {
1461 600 : if (!first)
1462 456 : appendStringInfoString(buf, ", ");
1463 144 : else if (is_returning)
1464 0 : appendStringInfoString(buf, " RETURNING ");
1465 600 : first = false;
1466 :
1467 600 : if (qualify_col)
1468 0 : ADD_REL_QUALIFIER(buf, rtindex);
1469 600 : appendStringInfoString(buf, "ctid");
1470 :
1471 600 : *retrieved_attrs = lappend_int(*retrieved_attrs,
1472 : SelfItemPointerAttributeNumber);
1473 : }
1474 :
1475 : /* Don't generate bad syntax if no undropped columns */
1476 3698 : if (first && !is_returning)
1477 86 : appendStringInfoString(buf, "NULL");
1478 3698 : }
1479 :
1480 : /*
1481 : * Deparse the appropriate locking clause (FOR UPDATE or FOR SHARE) for a
1482 : * given relation (context->scanrel).
1483 : */
1484 : static void
1485 4632 : deparseLockingClause(deparse_expr_cxt *context)
1486 : {
1487 4632 : StringInfo buf = context->buf;
1488 4632 : PlannerInfo *root = context->root;
1489 4632 : RelOptInfo *rel = context->scanrel;
1490 4632 : PgFdwRelationInfo *fpinfo = (PgFdwRelationInfo *) rel->fdw_private;
1491 4632 : int relid = -1;
1492 :
1493 11648 : while ((relid = bms_next_member(rel->relids, relid)) >= 0)
1494 : {
1495 : /*
1496 : * Ignore relation if it appears in a lower subquery. Locking clause
1497 : * for such a relation is included in the subquery if necessary.
1498 : */
1499 7016 : if (bms_is_member(relid, fpinfo->lower_subquery_rels))
1500 160 : continue;
1501 :
1502 : /*
1503 : * Add FOR UPDATE/SHARE if appropriate. We apply locking during the
1504 : * initial row fetch, rather than later on as is done for local
1505 : * tables. The extra roundtrips involved in trying to duplicate the
1506 : * local semantics exactly don't seem worthwhile (see also comments
1507 : * for RowMarkType).
1508 : *
1509 : * Note: because we actually run the query as a cursor, this assumes
1510 : * that DECLARE CURSOR ... FOR UPDATE is supported, which it isn't
1511 : * before 8.3.
1512 : */
1513 6856 : if (bms_is_member(relid, root->all_result_relids) &&
1514 618 : (root->parse->commandType == CMD_UPDATE ||
1515 248 : root->parse->commandType == CMD_DELETE))
1516 : {
1517 : /* Relation is UPDATE/DELETE target, so use FOR UPDATE */
1518 614 : appendStringInfoString(buf, " FOR UPDATE");
1519 :
1520 : /* Add the relation alias if we are here for a join relation */
1521 614 : if (IS_JOIN_REL(rel))
1522 108 : appendStringInfo(buf, " OF %s%d", REL_ALIAS_PREFIX, relid);
1523 : }
1524 : else
1525 : {
1526 6242 : PlanRowMark *rc = get_plan_rowmark(root->rowMarks, relid);
1527 :
1528 6242 : if (rc)
1529 : {
1530 : /*
1531 : * Relation is specified as a FOR UPDATE/SHARE target, so
1532 : * handle that. (But we could also see LCS_NONE, meaning this
1533 : * isn't a target relation after all.)
1534 : *
1535 : * For now, just ignore any [NO] KEY specification, since (a)
1536 : * it's not clear what that means for a remote table that we
1537 : * don't have complete information about, and (b) it wouldn't
1538 : * work anyway on older remote servers. Likewise, we don't
1539 : * worry about NOWAIT.
1540 : */
1541 720 : switch (rc->strength)
1542 : {
1543 392 : case LCS_NONE:
1544 : /* No locking needed */
1545 392 : break;
1546 76 : case LCS_FORKEYSHARE:
1547 : case LCS_FORSHARE:
1548 76 : appendStringInfoString(buf, " FOR SHARE");
1549 76 : break;
1550 252 : case LCS_FORNOKEYUPDATE:
1551 : case LCS_FORUPDATE:
1552 252 : appendStringInfoString(buf, " FOR UPDATE");
1553 252 : break;
1554 : }
1555 :
1556 : /* Add the relation alias if we are here for a join relation */
1557 720 : if (bms_membership(rel->relids) == BMS_MULTIPLE &&
1558 424 : rc->strength != LCS_NONE)
1559 220 : appendStringInfo(buf, " OF %s%d", REL_ALIAS_PREFIX, relid);
1560 : }
1561 : }
1562 : }
1563 4632 : }
1564 :
1565 : /*
1566 : * Deparse conditions from the provided list and append them to buf.
1567 : *
1568 : * The conditions in the list are assumed to be ANDed. This function is used to
1569 : * deparse WHERE clauses, JOIN .. ON clauses and HAVING clauses.
1570 : *
1571 : * Depending on the caller, the list elements might be either RestrictInfos
1572 : * or bare clauses.
1573 : */
1574 : static void
1575 3796 : appendConditions(List *exprs, deparse_expr_cxt *context)
1576 : {
1577 : int nestlevel;
1578 : ListCell *lc;
1579 3796 : bool is_first = true;
1580 3796 : StringInfo buf = context->buf;
1581 :
1582 : /* Make sure any constants in the exprs are printed portably */
1583 3796 : nestlevel = set_transmission_modes();
1584 :
1585 8710 : foreach(lc, exprs)
1586 : {
1587 4914 : Expr *expr = (Expr *) lfirst(lc);
1588 :
1589 : /* Extract clause from RestrictInfo, if required */
1590 4914 : if (IsA(expr, RestrictInfo))
1591 4196 : expr = ((RestrictInfo *) expr)->clause;
1592 :
1593 : /* Connect expressions with "AND" and parenthesize each condition. */
1594 4914 : if (!is_first)
1595 1118 : appendStringInfoString(buf, " AND ");
1596 :
1597 4914 : appendStringInfoChar(buf, '(');
1598 4914 : deparseExpr(expr, context);
1599 4914 : appendStringInfoChar(buf, ')');
1600 :
1601 4914 : is_first = false;
1602 : }
1603 :
1604 3796 : reset_transmission_modes(nestlevel);
1605 3796 : }
1606 :
1607 : /*
1608 : * Append WHERE clause, containing conditions from exprs and additional_conds,
1609 : * to context->buf.
1610 : */
1611 : static void
1612 5220 : appendWhereClause(List *exprs, List *additional_conds, deparse_expr_cxt *context)
1613 : {
1614 5220 : StringInfo buf = context->buf;
1615 5220 : bool need_and = false;
1616 : ListCell *lc;
1617 :
1618 5220 : if (exprs != NIL || additional_conds != NIL)
1619 2486 : appendStringInfoString(buf, " WHERE ");
1620 :
1621 : /*
1622 : * If there are some filters, append them.
1623 : */
1624 5220 : if (exprs != NIL)
1625 : {
1626 2280 : appendConditions(exprs, context);
1627 2280 : need_and = true;
1628 : }
1629 :
1630 : /*
1631 : * If there are some EXISTS conditions, coming from SEMI-JOINS, append
1632 : * them.
1633 : */
1634 5600 : foreach(lc, additional_conds)
1635 : {
1636 380 : if (need_and)
1637 174 : appendStringInfoString(buf, " AND ");
1638 380 : appendStringInfoString(buf, (char *) lfirst(lc));
1639 380 : need_and = true;
1640 : }
1641 5220 : }
1642 :
1643 : /* Output join name for given join type */
1644 : const char *
1645 2190 : get_jointype_name(JoinType jointype)
1646 : {
1647 2190 : switch (jointype)
1648 : {
1649 1454 : case JOIN_INNER:
1650 1454 : return "INNER";
1651 :
1652 432 : case JOIN_LEFT:
1653 432 : return "LEFT";
1654 :
1655 0 : case JOIN_RIGHT:
1656 0 : return "RIGHT";
1657 :
1658 216 : case JOIN_FULL:
1659 216 : return "FULL";
1660 :
1661 88 : case JOIN_SEMI:
1662 88 : return "SEMI";
1663 :
1664 0 : default:
1665 : /* Shouldn't come here, but protect from buggy code. */
1666 0 : elog(ERROR, "unsupported join type %d", jointype);
1667 : }
1668 :
1669 : /* Keep compiler happy */
1670 : return NULL;
1671 : }
1672 :
1673 : /*
1674 : * Deparse given targetlist and append it to context->buf.
1675 : *
1676 : * tlist is list of TargetEntry's which in turn contain Var nodes.
1677 : *
1678 : * retrieved_attrs is the list of continuously increasing integers starting
1679 : * from 1. It has same number of entries as tlist.
1680 : *
1681 : * This is used for both SELECT and RETURNING targetlists; the is_returning
1682 : * parameter is true only for a RETURNING targetlist.
1683 : */
1684 : static void
1685 1618 : deparseExplicitTargetList(List *tlist,
1686 : bool is_returning,
1687 : List **retrieved_attrs,
1688 : deparse_expr_cxt *context)
1689 : {
1690 : ListCell *lc;
1691 1618 : StringInfo buf = context->buf;
1692 1618 : int i = 0;
1693 :
1694 1618 : *retrieved_attrs = NIL;
1695 :
1696 9564 : foreach(lc, tlist)
1697 : {
1698 7946 : TargetEntry *tle = lfirst_node(TargetEntry, lc);
1699 :
1700 7946 : if (i > 0)
1701 6344 : appendStringInfoString(buf, ", ");
1702 1602 : else if (is_returning)
1703 4 : appendStringInfoString(buf, " RETURNING ");
1704 :
1705 7946 : deparseExpr((Expr *) tle->expr, context);
1706 :
1707 7946 : *retrieved_attrs = lappend_int(*retrieved_attrs, i + 1);
1708 7946 : i++;
1709 : }
1710 :
1711 1618 : if (i == 0 && !is_returning)
1712 4 : appendStringInfoString(buf, "NULL");
1713 1618 : }
1714 :
1715 : /*
1716 : * Emit expressions specified in the given relation's reltarget.
1717 : *
1718 : * This is used for deparsing the given relation as a subquery.
1719 : */
1720 : static void
1721 100 : deparseSubqueryTargetList(deparse_expr_cxt *context)
1722 : {
1723 100 : StringInfo buf = context->buf;
1724 100 : RelOptInfo *foreignrel = context->foreignrel;
1725 : bool first;
1726 : ListCell *lc;
1727 :
1728 : /* Should only be called in these cases. */
1729 : Assert(IS_SIMPLE_REL(foreignrel) || IS_JOIN_REL(foreignrel));
1730 :
1731 100 : first = true;
1732 240 : foreach(lc, foreignrel->reltarget->exprs)
1733 : {
1734 140 : Node *node = (Node *) lfirst(lc);
1735 :
1736 140 : if (!first)
1737 48 : appendStringInfoString(buf, ", ");
1738 140 : first = false;
1739 :
1740 140 : deparseExpr((Expr *) node, context);
1741 : }
1742 :
1743 : /* Don't generate bad syntax if no expressions */
1744 100 : if (first)
1745 8 : appendStringInfoString(buf, "NULL");
1746 100 : }
1747 :
1748 : /*
1749 : * Construct FROM clause for given relation
1750 : *
1751 : * The function constructs ... JOIN ... ON ... for join relation. For a base
1752 : * relation it just returns schema-qualified tablename, with the appropriate
1753 : * alias if so requested.
1754 : *
1755 : * 'ignore_rel' is either zero or the RT index of a target relation. In the
1756 : * latter case the function constructs FROM clause of UPDATE or USING clause
1757 : * of DELETE; it deparses the join relation as if the relation never contained
1758 : * the target relation, and creates a List of conditions to be deparsed into
1759 : * the top-level WHERE clause, which is returned to *ignore_conds.
1760 : *
1761 : * 'additional_conds' is a pointer to a list of strings to be appended to
1762 : * the WHERE clause, coming from lower-level SEMI-JOINs.
1763 : */
1764 : static void
1765 8372 : deparseFromExprForRel(StringInfo buf, PlannerInfo *root, RelOptInfo *foreignrel,
1766 : bool use_alias, Index ignore_rel, List **ignore_conds,
1767 : List **additional_conds, List **params_list)
1768 : {
1769 8372 : PgFdwRelationInfo *fpinfo = (PgFdwRelationInfo *) foreignrel->fdw_private;
1770 :
1771 8372 : if (IS_JOIN_REL(foreignrel))
1772 1904 : {
1773 : StringInfoData join_sql_o;
1774 : StringInfoData join_sql_i;
1775 1920 : RelOptInfo *outerrel = fpinfo->outerrel;
1776 1920 : RelOptInfo *innerrel = fpinfo->innerrel;
1777 1920 : bool outerrel_is_target = false;
1778 1920 : bool innerrel_is_target = false;
1779 1920 : List *additional_conds_i = NIL;
1780 1920 : List *additional_conds_o = NIL;
1781 :
1782 1920 : if (ignore_rel > 0 && bms_is_member(ignore_rel, foreignrel->relids))
1783 : {
1784 : /*
1785 : * If this is an inner join, add joinclauses to *ignore_conds and
1786 : * set it to empty so that those can be deparsed into the WHERE
1787 : * clause. Note that since the target relation can never be
1788 : * within the nullable side of an outer join, those could safely
1789 : * be pulled up into the WHERE clause (see foreign_join_ok()).
1790 : * Note also that since the target relation is only inner-joined
1791 : * to any other relation in the query, all conditions in the join
1792 : * tree mentioning the target relation could be deparsed into the
1793 : * WHERE clause by doing this recursively.
1794 : */
1795 24 : if (fpinfo->jointype == JOIN_INNER)
1796 : {
1797 40 : *ignore_conds = list_concat(*ignore_conds,
1798 20 : fpinfo->joinclauses);
1799 20 : fpinfo->joinclauses = NIL;
1800 : }
1801 :
1802 : /*
1803 : * Check if either of the input relations is the target relation.
1804 : */
1805 24 : if (outerrel->relid == ignore_rel)
1806 16 : outerrel_is_target = true;
1807 8 : else if (innerrel->relid == ignore_rel)
1808 0 : innerrel_is_target = true;
1809 : }
1810 :
1811 : /* Deparse outer relation if not the target relation. */
1812 1920 : if (!outerrel_is_target)
1813 : {
1814 1904 : initStringInfo(&join_sql_o);
1815 1904 : deparseRangeTblRef(&join_sql_o, root, outerrel,
1816 1904 : fpinfo->make_outerrel_subquery,
1817 : ignore_rel, ignore_conds, &additional_conds_o,
1818 : params_list);
1819 :
1820 : /*
1821 : * If inner relation is the target relation, skip deparsing it.
1822 : * Note that since the join of the target relation with any other
1823 : * relation in the query is an inner join and can never be within
1824 : * the nullable side of an outer join, the join could be
1825 : * interchanged with higher-level joins (cf. identity 1 on outer
1826 : * join reordering shown in src/backend/optimizer/README), which
1827 : * means it's safe to skip the target-relation deparsing here.
1828 : */
1829 1904 : if (innerrel_is_target)
1830 : {
1831 : Assert(fpinfo->jointype == JOIN_INNER);
1832 : Assert(fpinfo->joinclauses == NIL);
1833 0 : appendBinaryStringInfo(buf, join_sql_o.data, join_sql_o.len);
1834 : /* Pass EXISTS conditions to upper level */
1835 0 : if (additional_conds_o != NIL)
1836 : {
1837 : Assert(*additional_conds == NIL);
1838 0 : *additional_conds = additional_conds_o;
1839 : }
1840 16 : return;
1841 : }
1842 : }
1843 :
1844 : /* Deparse inner relation if not the target relation. */
1845 1920 : if (!innerrel_is_target)
1846 : {
1847 1920 : initStringInfo(&join_sql_i);
1848 1920 : deparseRangeTblRef(&join_sql_i, root, innerrel,
1849 1920 : fpinfo->make_innerrel_subquery,
1850 : ignore_rel, ignore_conds, &additional_conds_i,
1851 : params_list);
1852 :
1853 : /*
1854 : * SEMI-JOIN is deparsed as the EXISTS subquery. It references
1855 : * outer and inner relations, so it should be evaluated as the
1856 : * condition in the upper-level WHERE clause. We deparse the
1857 : * condition and pass it to upper level callers as an
1858 : * additional_conds list. Upper level callers are responsible for
1859 : * inserting conditions from the list where appropriate.
1860 : */
1861 1920 : if (fpinfo->jointype == JOIN_SEMI)
1862 : {
1863 : deparse_expr_cxt context;
1864 : StringInfoData str;
1865 :
1866 : /* Construct deparsed condition from this SEMI-JOIN */
1867 380 : initStringInfo(&str);
1868 380 : appendStringInfo(&str, "EXISTS (SELECT NULL FROM %s",
1869 : join_sql_i.data);
1870 :
1871 380 : context.buf = &str;
1872 380 : context.foreignrel = foreignrel;
1873 380 : context.scanrel = foreignrel;
1874 380 : context.root = root;
1875 380 : context.params_list = params_list;
1876 :
1877 : /*
1878 : * Append SEMI-JOIN clauses and EXISTS conditions from lower
1879 : * levels to the current EXISTS subquery
1880 : */
1881 380 : appendWhereClause(fpinfo->joinclauses, additional_conds_i, &context);
1882 :
1883 : /*
1884 : * EXISTS conditions, coming from lower join levels, have just
1885 : * been processed.
1886 : */
1887 380 : if (additional_conds_i != NIL)
1888 : {
1889 32 : list_free_deep(additional_conds_i);
1890 32 : additional_conds_i = NIL;
1891 : }
1892 :
1893 : /* Close parentheses for EXISTS subquery */
1894 380 : appendStringInfoChar(&str, ')');
1895 :
1896 380 : *additional_conds = lappend(*additional_conds, str.data);
1897 : }
1898 :
1899 : /*
1900 : * If outer relation is the target relation, skip deparsing it.
1901 : * See the above note about safety.
1902 : */
1903 1920 : if (outerrel_is_target)
1904 : {
1905 : Assert(fpinfo->jointype == JOIN_INNER);
1906 : Assert(fpinfo->joinclauses == NIL);
1907 16 : appendBinaryStringInfo(buf, join_sql_i.data, join_sql_i.len);
1908 : /* Pass EXISTS conditions to the upper call */
1909 16 : if (additional_conds_i != NIL)
1910 : {
1911 : Assert(*additional_conds == NIL);
1912 0 : *additional_conds = additional_conds_i;
1913 : }
1914 16 : return;
1915 : }
1916 : }
1917 :
1918 : /* Neither of the relations is the target relation. */
1919 : Assert(!outerrel_is_target && !innerrel_is_target);
1920 :
1921 : /*
1922 : * For semijoin FROM clause is deparsed as an outer relation. An inner
1923 : * relation and join clauses are converted to EXISTS condition and
1924 : * passed to the upper level.
1925 : */
1926 1904 : if (fpinfo->jointype == JOIN_SEMI)
1927 : {
1928 380 : appendBinaryStringInfo(buf, join_sql_o.data, join_sql_o.len);
1929 : }
1930 : else
1931 : {
1932 : /*
1933 : * For a join relation FROM clause, entry is deparsed as
1934 : *
1935 : * ((outer relation) <join type> (inner relation) ON
1936 : * (joinclauses))
1937 : */
1938 1524 : appendStringInfo(buf, "(%s %s JOIN %s ON ", join_sql_o.data,
1939 : get_jointype_name(fpinfo->jointype), join_sql_i.data);
1940 :
1941 : /* Append join clause; (TRUE) if no join clause */
1942 1524 : if (fpinfo->joinclauses)
1943 : {
1944 : deparse_expr_cxt context;
1945 :
1946 1480 : context.buf = buf;
1947 1480 : context.foreignrel = foreignrel;
1948 1480 : context.scanrel = foreignrel;
1949 1480 : context.root = root;
1950 1480 : context.params_list = params_list;
1951 :
1952 1480 : appendStringInfoChar(buf, '(');
1953 1480 : appendConditions(fpinfo->joinclauses, &context);
1954 1480 : appendStringInfoChar(buf, ')');
1955 : }
1956 : else
1957 44 : appendStringInfoString(buf, "(TRUE)");
1958 :
1959 : /* End the FROM clause entry. */
1960 1524 : appendStringInfoChar(buf, ')');
1961 : }
1962 :
1963 : /*
1964 : * Construct additional_conds to be passed to the upper caller from
1965 : * current level additional_conds and additional_conds, coming from
1966 : * inner and outer rels.
1967 : */
1968 1904 : if (additional_conds_o != NIL)
1969 : {
1970 96 : *additional_conds = list_concat(*additional_conds,
1971 : additional_conds_o);
1972 96 : list_free(additional_conds_o);
1973 : }
1974 :
1975 1904 : if (additional_conds_i != NIL)
1976 : {
1977 0 : *additional_conds = list_concat(*additional_conds,
1978 : additional_conds_i);
1979 0 : list_free(additional_conds_i);
1980 : }
1981 : }
1982 : else
1983 : {
1984 6452 : RangeTblEntry *rte = planner_rt_fetch(foreignrel->relid, root);
1985 :
1986 : /*
1987 : * Core code already has some lock on each rel being planned, so we
1988 : * can use NoLock here.
1989 : */
1990 6452 : Relation rel = table_open(rte->relid, NoLock);
1991 :
1992 6452 : deparseRelation(buf, rel);
1993 :
1994 : /*
1995 : * Add a unique alias to avoid any conflict in relation names due to
1996 : * pulled up subqueries in the query being built for a pushed down
1997 : * join.
1998 : */
1999 6452 : if (use_alias)
2000 3180 : appendStringInfo(buf, " %s%d", REL_ALIAS_PREFIX, foreignrel->relid);
2001 :
2002 6452 : table_close(rel, NoLock);
2003 : }
2004 : }
2005 :
2006 : /*
2007 : * Append FROM clause entry for the given relation into buf.
2008 : * Conditions from lower-level SEMI-JOINs are appended to additional_conds
2009 : * and should be added to upper level WHERE clause.
2010 : */
2011 : static void
2012 3824 : deparseRangeTblRef(StringInfo buf, PlannerInfo *root, RelOptInfo *foreignrel,
2013 : bool make_subquery, Index ignore_rel, List **ignore_conds,
2014 : List **additional_conds, List **params_list)
2015 : {
2016 3824 : PgFdwRelationInfo *fpinfo = (PgFdwRelationInfo *) foreignrel->fdw_private;
2017 :
2018 : /* Should only be called in these cases. */
2019 : Assert(IS_SIMPLE_REL(foreignrel) || IS_JOIN_REL(foreignrel));
2020 :
2021 : Assert(fpinfo->local_conds == NIL);
2022 :
2023 : /* If make_subquery is true, deparse the relation as a subquery. */
2024 3824 : if (make_subquery)
2025 : {
2026 : List *retrieved_attrs;
2027 : int ncols;
2028 :
2029 : /*
2030 : * The given relation shouldn't contain the target relation, because
2031 : * this should only happen for input relations for a full join, and
2032 : * such relations can never contain an UPDATE/DELETE target.
2033 : */
2034 : Assert(ignore_rel == 0 ||
2035 : !bms_is_member(ignore_rel, foreignrel->relids));
2036 :
2037 : /* Deparse the subquery representing the relation. */
2038 100 : appendStringInfoChar(buf, '(');
2039 100 : deparseSelectStmtForRel(buf, root, foreignrel, NIL,
2040 : fpinfo->remote_conds, NIL,
2041 : false, false, true,
2042 : &retrieved_attrs, params_list);
2043 100 : appendStringInfoChar(buf, ')');
2044 :
2045 : /* Append the relation alias. */
2046 100 : appendStringInfo(buf, " %s%d", SUBQUERY_REL_ALIAS_PREFIX,
2047 : fpinfo->relation_index);
2048 :
2049 : /*
2050 : * Append the column aliases if needed. Note that the subquery emits
2051 : * expressions specified in the relation's reltarget (see
2052 : * deparseSubqueryTargetList).
2053 : */
2054 100 : ncols = list_length(foreignrel->reltarget->exprs);
2055 100 : if (ncols > 0)
2056 : {
2057 : int i;
2058 :
2059 92 : appendStringInfoChar(buf, '(');
2060 232 : for (i = 1; i <= ncols; i++)
2061 : {
2062 140 : if (i > 1)
2063 48 : appendStringInfoString(buf, ", ");
2064 :
2065 140 : appendStringInfo(buf, "%s%d", SUBQUERY_COL_ALIAS_PREFIX, i);
2066 : }
2067 92 : appendStringInfoChar(buf, ')');
2068 : }
2069 : }
2070 : else
2071 3724 : deparseFromExprForRel(buf, root, foreignrel, true, ignore_rel,
2072 : ignore_conds, additional_conds,
2073 : params_list);
2074 3824 : }
2075 :
2076 : /*
2077 : * deparse remote INSERT statement
2078 : *
2079 : * The statement text is appended to buf, and we also create an integer List
2080 : * of the columns being retrieved by WITH CHECK OPTION or RETURNING (if any),
2081 : * which is returned to *retrieved_attrs.
2082 : *
2083 : * This also stores end position of the VALUES clause, so that we can rebuild
2084 : * an INSERT for a batch of rows later.
2085 : */
2086 : void
2087 282 : deparseInsertSql(StringInfo buf, RangeTblEntry *rte,
2088 : Index rtindex, Relation rel,
2089 : List *targetAttrs, bool doNothing,
2090 : List *withCheckOptionList, List *returningList,
2091 : List **retrieved_attrs, int *values_end_len)
2092 : {
2093 282 : TupleDesc tupdesc = RelationGetDescr(rel);
2094 : AttrNumber pindex;
2095 : bool first;
2096 : ListCell *lc;
2097 :
2098 282 : appendStringInfoString(buf, "INSERT INTO ");
2099 282 : deparseRelation(buf, rel);
2100 :
2101 282 : if (targetAttrs)
2102 : {
2103 280 : appendStringInfoChar(buf, '(');
2104 :
2105 280 : first = true;
2106 1050 : foreach(lc, targetAttrs)
2107 : {
2108 770 : int attnum = lfirst_int(lc);
2109 :
2110 770 : if (!first)
2111 490 : appendStringInfoString(buf, ", ");
2112 770 : first = false;
2113 :
2114 770 : deparseColumnRef(buf, rtindex, attnum, rte, false);
2115 : }
2116 :
2117 280 : appendStringInfoString(buf, ") VALUES (");
2118 :
2119 280 : pindex = 1;
2120 280 : first = true;
2121 1050 : foreach(lc, targetAttrs)
2122 : {
2123 770 : int attnum = lfirst_int(lc);
2124 770 : Form_pg_attribute attr = TupleDescAttr(tupdesc, attnum - 1);
2125 :
2126 770 : if (!first)
2127 490 : appendStringInfoString(buf, ", ");
2128 770 : first = false;
2129 :
2130 770 : if (attr->attgenerated)
2131 20 : appendStringInfoString(buf, "DEFAULT");
2132 : else
2133 : {
2134 750 : appendStringInfo(buf, "$%d", pindex);
2135 750 : pindex++;
2136 : }
2137 : }
2138 :
2139 280 : appendStringInfoChar(buf, ')');
2140 : }
2141 : else
2142 2 : appendStringInfoString(buf, " DEFAULT VALUES");
2143 282 : *values_end_len = buf->len;
2144 :
2145 282 : if (doNothing)
2146 6 : appendStringInfoString(buf, " ON CONFLICT DO NOTHING");
2147 :
2148 282 : deparseReturningList(buf, rte, rtindex, rel,
2149 282 : rel->trigdesc && rel->trigdesc->trig_insert_after_row,
2150 : withCheckOptionList, returningList, retrieved_attrs);
2151 282 : }
2152 :
2153 : /*
2154 : * rebuild remote INSERT statement
2155 : *
2156 : * Provided a number of rows in a batch, builds INSERT statement with the
2157 : * right number of parameters.
2158 : */
2159 : void
2160 52 : rebuildInsertSql(StringInfo buf, Relation rel,
2161 : char *orig_query, List *target_attrs,
2162 : int values_end_len, int num_params,
2163 : int num_rows)
2164 : {
2165 52 : TupleDesc tupdesc = RelationGetDescr(rel);
2166 : int i;
2167 : int pindex;
2168 : bool first;
2169 : ListCell *lc;
2170 :
2171 : /* Make sure the values_end_len is sensible */
2172 : Assert((values_end_len > 0) && (values_end_len <= strlen(orig_query)));
2173 :
2174 : /* Copy up to the end of the first record from the original query */
2175 52 : appendBinaryStringInfo(buf, orig_query, values_end_len);
2176 :
2177 : /*
2178 : * Add records to VALUES clause (we already have parameters for the first
2179 : * row, so start at the right offset).
2180 : */
2181 52 : pindex = num_params + 1;
2182 206 : for (i = 0; i < num_rows; i++)
2183 : {
2184 154 : appendStringInfoString(buf, ", (");
2185 :
2186 154 : first = true;
2187 452 : foreach(lc, target_attrs)
2188 : {
2189 298 : int attnum = lfirst_int(lc);
2190 298 : Form_pg_attribute attr = TupleDescAttr(tupdesc, attnum - 1);
2191 :
2192 298 : if (!first)
2193 144 : appendStringInfoString(buf, ", ");
2194 298 : first = false;
2195 :
2196 298 : if (attr->attgenerated)
2197 4 : appendStringInfoString(buf, "DEFAULT");
2198 : else
2199 : {
2200 294 : appendStringInfo(buf, "$%d", pindex);
2201 294 : pindex++;
2202 : }
2203 : }
2204 :
2205 154 : appendStringInfoChar(buf, ')');
2206 : }
2207 :
2208 : /* Copy stuff after VALUES clause from the original query */
2209 52 : appendStringInfoString(buf, orig_query + values_end_len);
2210 52 : }
2211 :
2212 : /*
2213 : * deparse remote UPDATE statement
2214 : *
2215 : * The statement text is appended to buf, and we also create an integer List
2216 : * of the columns being retrieved by WITH CHECK OPTION or RETURNING (if any),
2217 : * which is returned to *retrieved_attrs.
2218 : */
2219 : void
2220 112 : deparseUpdateSql(StringInfo buf, RangeTblEntry *rte,
2221 : Index rtindex, Relation rel,
2222 : List *targetAttrs,
2223 : List *withCheckOptionList, List *returningList,
2224 : List **retrieved_attrs)
2225 : {
2226 112 : TupleDesc tupdesc = RelationGetDescr(rel);
2227 : AttrNumber pindex;
2228 : bool first;
2229 : ListCell *lc;
2230 :
2231 112 : appendStringInfoString(buf, "UPDATE ");
2232 112 : deparseRelation(buf, rel);
2233 112 : appendStringInfoString(buf, " SET ");
2234 :
2235 112 : pindex = 2; /* ctid is always the first param */
2236 112 : first = true;
2237 278 : foreach(lc, targetAttrs)
2238 : {
2239 166 : int attnum = lfirst_int(lc);
2240 166 : Form_pg_attribute attr = TupleDescAttr(tupdesc, attnum - 1);
2241 :
2242 166 : if (!first)
2243 54 : appendStringInfoString(buf, ", ");
2244 166 : first = false;
2245 :
2246 166 : deparseColumnRef(buf, rtindex, attnum, rte, false);
2247 166 : if (attr->attgenerated)
2248 8 : appendStringInfoString(buf, " = DEFAULT");
2249 : else
2250 : {
2251 158 : appendStringInfo(buf, " = $%d", pindex);
2252 158 : pindex++;
2253 : }
2254 : }
2255 112 : appendStringInfoString(buf, " WHERE ctid = $1");
2256 :
2257 112 : deparseReturningList(buf, rte, rtindex, rel,
2258 112 : rel->trigdesc && rel->trigdesc->trig_update_after_row,
2259 : withCheckOptionList, returningList, retrieved_attrs);
2260 112 : }
2261 :
2262 : /*
2263 : * deparse remote UPDATE statement
2264 : *
2265 : * 'buf' is the output buffer to append the statement to
2266 : * 'rtindex' is the RT index of the associated target relation
2267 : * 'rel' is the relation descriptor for the target relation
2268 : * 'foreignrel' is the RelOptInfo for the target relation or the join relation
2269 : * containing all base relations in the query
2270 : * 'targetlist' is the tlist of the underlying foreign-scan plan node
2271 : * (note that this only contains new-value expressions and junk attrs)
2272 : * 'targetAttrs' is the target columns of the UPDATE
2273 : * 'remote_conds' is the qual clauses that must be evaluated remotely
2274 : * '*params_list' is an output list of exprs that will become remote Params
2275 : * 'returningList' is the RETURNING targetlist
2276 : * '*retrieved_attrs' is an output list of integers of columns being retrieved
2277 : * by RETURNING (if any)
2278 : */
2279 : void
2280 90 : deparseDirectUpdateSql(StringInfo buf, PlannerInfo *root,
2281 : Index rtindex, Relation rel,
2282 : RelOptInfo *foreignrel,
2283 : List *targetlist,
2284 : List *targetAttrs,
2285 : List *remote_conds,
2286 : List **params_list,
2287 : List *returningList,
2288 : List **retrieved_attrs)
2289 : {
2290 : deparse_expr_cxt context;
2291 : int nestlevel;
2292 : bool first;
2293 90 : RangeTblEntry *rte = planner_rt_fetch(rtindex, root);
2294 : ListCell *lc,
2295 : *lc2;
2296 90 : List *additional_conds = NIL;
2297 :
2298 : /* Set up context struct for recursion */
2299 90 : context.root = root;
2300 90 : context.foreignrel = foreignrel;
2301 90 : context.scanrel = foreignrel;
2302 90 : context.buf = buf;
2303 90 : context.params_list = params_list;
2304 :
2305 90 : appendStringInfoString(buf, "UPDATE ");
2306 90 : deparseRelation(buf, rel);
2307 90 : if (foreignrel->reloptkind == RELOPT_JOINREL)
2308 8 : appendStringInfo(buf, " %s%d", REL_ALIAS_PREFIX, rtindex);
2309 90 : appendStringInfoString(buf, " SET ");
2310 :
2311 : /* Make sure any constants in the exprs are printed portably */
2312 90 : nestlevel = set_transmission_modes();
2313 :
2314 90 : first = true;
2315 196 : forboth(lc, targetlist, lc2, targetAttrs)
2316 : {
2317 106 : TargetEntry *tle = lfirst_node(TargetEntry, lc);
2318 106 : int attnum = lfirst_int(lc2);
2319 :
2320 : /* update's new-value expressions shouldn't be resjunk */
2321 : Assert(!tle->resjunk);
2322 :
2323 106 : if (!first)
2324 16 : appendStringInfoString(buf, ", ");
2325 106 : first = false;
2326 :
2327 106 : deparseColumnRef(buf, rtindex, attnum, rte, false);
2328 106 : appendStringInfoString(buf, " = ");
2329 106 : deparseExpr((Expr *) tle->expr, &context);
2330 : }
2331 :
2332 90 : reset_transmission_modes(nestlevel);
2333 :
2334 90 : if (foreignrel->reloptkind == RELOPT_JOINREL)
2335 : {
2336 8 : List *ignore_conds = NIL;
2337 :
2338 :
2339 8 : appendStringInfoString(buf, " FROM ");
2340 8 : deparseFromExprForRel(buf, root, foreignrel, true, rtindex,
2341 : &ignore_conds, &additional_conds, params_list);
2342 8 : remote_conds = list_concat(remote_conds, ignore_conds);
2343 : }
2344 :
2345 90 : appendWhereClause(remote_conds, additional_conds, &context);
2346 :
2347 90 : if (additional_conds != NIL)
2348 0 : list_free_deep(additional_conds);
2349 :
2350 90 : if (foreignrel->reloptkind == RELOPT_JOINREL)
2351 8 : deparseExplicitTargetList(returningList, true, retrieved_attrs,
2352 : &context);
2353 : else
2354 82 : deparseReturningList(buf, rte, rtindex, rel, false,
2355 : NIL, returningList, retrieved_attrs);
2356 90 : }
2357 :
2358 : /*
2359 : * deparse remote DELETE statement
2360 : *
2361 : * The statement text is appended to buf, and we also create an integer List
2362 : * of the columns being retrieved by RETURNING (if any), which is returned
2363 : * to *retrieved_attrs.
2364 : */
2365 : void
2366 36 : deparseDeleteSql(StringInfo buf, RangeTblEntry *rte,
2367 : Index rtindex, Relation rel,
2368 : List *returningList,
2369 : List **retrieved_attrs)
2370 : {
2371 36 : appendStringInfoString(buf, "DELETE FROM ");
2372 36 : deparseRelation(buf, rel);
2373 36 : appendStringInfoString(buf, " WHERE ctid = $1");
2374 :
2375 36 : deparseReturningList(buf, rte, rtindex, rel,
2376 36 : rel->trigdesc && rel->trigdesc->trig_delete_after_row,
2377 : NIL, returningList, retrieved_attrs);
2378 36 : }
2379 :
2380 : /*
2381 : * deparse remote DELETE statement
2382 : *
2383 : * 'buf' is the output buffer to append the statement to
2384 : * 'rtindex' is the RT index of the associated target relation
2385 : * 'rel' is the relation descriptor for the target relation
2386 : * 'foreignrel' is the RelOptInfo for the target relation or the join relation
2387 : * containing all base relations in the query
2388 : * 'remote_conds' is the qual clauses that must be evaluated remotely
2389 : * '*params_list' is an output list of exprs that will become remote Params
2390 : * 'returningList' is the RETURNING targetlist
2391 : * '*retrieved_attrs' is an output list of integers of columns being retrieved
2392 : * by RETURNING (if any)
2393 : */
2394 : void
2395 118 : deparseDirectDeleteSql(StringInfo buf, PlannerInfo *root,
2396 : Index rtindex, Relation rel,
2397 : RelOptInfo *foreignrel,
2398 : List *remote_conds,
2399 : List **params_list,
2400 : List *returningList,
2401 : List **retrieved_attrs)
2402 : {
2403 : deparse_expr_cxt context;
2404 118 : List *additional_conds = NIL;
2405 :
2406 : /* Set up context struct for recursion */
2407 118 : context.root = root;
2408 118 : context.foreignrel = foreignrel;
2409 118 : context.scanrel = foreignrel;
2410 118 : context.buf = buf;
2411 118 : context.params_list = params_list;
2412 :
2413 118 : appendStringInfoString(buf, "DELETE FROM ");
2414 118 : deparseRelation(buf, rel);
2415 118 : if (foreignrel->reloptkind == RELOPT_JOINREL)
2416 8 : appendStringInfo(buf, " %s%d", REL_ALIAS_PREFIX, rtindex);
2417 :
2418 118 : if (foreignrel->reloptkind == RELOPT_JOINREL)
2419 : {
2420 8 : List *ignore_conds = NIL;
2421 :
2422 8 : appendStringInfoString(buf, " USING ");
2423 8 : deparseFromExprForRel(buf, root, foreignrel, true, rtindex,
2424 : &ignore_conds, &additional_conds, params_list);
2425 8 : remote_conds = list_concat(remote_conds, ignore_conds);
2426 : }
2427 :
2428 118 : appendWhereClause(remote_conds, additional_conds, &context);
2429 :
2430 118 : if (additional_conds != NIL)
2431 0 : list_free_deep(additional_conds);
2432 :
2433 118 : if (foreignrel->reloptkind == RELOPT_JOINREL)
2434 8 : deparseExplicitTargetList(returningList, true, retrieved_attrs,
2435 : &context);
2436 : else
2437 110 : deparseReturningList(buf, planner_rt_fetch(rtindex, root),
2438 : rtindex, rel, false,
2439 : NIL, returningList, retrieved_attrs);
2440 118 : }
2441 :
2442 : /*
2443 : * Add a RETURNING clause, if needed, to an INSERT/UPDATE/DELETE.
2444 : */
2445 : static void
2446 622 : deparseReturningList(StringInfo buf, RangeTblEntry *rte,
2447 : Index rtindex, Relation rel,
2448 : bool trig_after_row,
2449 : List *withCheckOptionList,
2450 : List *returningList,
2451 : List **retrieved_attrs)
2452 : {
2453 622 : Bitmapset *attrs_used = NULL;
2454 :
2455 622 : if (trig_after_row)
2456 : {
2457 : /* whole-row reference acquires all non-system columns */
2458 48 : attrs_used =
2459 48 : bms_make_singleton(0 - FirstLowInvalidHeapAttributeNumber);
2460 : }
2461 :
2462 622 : if (withCheckOptionList != NIL)
2463 : {
2464 : /*
2465 : * We need the attrs, non-system and system, mentioned in the local
2466 : * query's WITH CHECK OPTION list.
2467 : *
2468 : * Note: we do this to ensure that WCO constraints will be evaluated
2469 : * on the data actually inserted/updated on the remote side, which
2470 : * might differ from the data supplied by the core code, for example
2471 : * as a result of remote triggers.
2472 : */
2473 38 : pull_varattnos((Node *) withCheckOptionList, rtindex,
2474 : &attrs_used);
2475 : }
2476 :
2477 622 : if (returningList != NIL)
2478 : {
2479 : /*
2480 : * We need the attrs, non-system and system, mentioned in the local
2481 : * query's RETURNING list.
2482 : */
2483 152 : pull_varattnos((Node *) returningList, rtindex,
2484 : &attrs_used);
2485 : }
2486 :
2487 622 : if (attrs_used != NULL)
2488 236 : deparseTargetList(buf, rte, rtindex, rel, true, attrs_used, false,
2489 : retrieved_attrs);
2490 : else
2491 386 : *retrieved_attrs = NIL;
2492 622 : }
2493 :
2494 : /*
2495 : * Construct SELECT statement to acquire size in blocks of given relation.
2496 : *
2497 : * Note: we use local definition of block size, not remote definition.
2498 : * This is perhaps debatable.
2499 : *
2500 : * Note: pg_relation_size() exists in 8.1 and later.
2501 : */
2502 : void
2503 84 : deparseAnalyzeSizeSql(StringInfo buf, Relation rel)
2504 : {
2505 : StringInfoData relname;
2506 :
2507 : /* We'll need the remote relation name as a literal. */
2508 84 : initStringInfo(&relname);
2509 84 : deparseRelation(&relname, rel);
2510 :
2511 84 : appendStringInfoString(buf, "SELECT pg_catalog.pg_relation_size(");
2512 84 : deparseStringLiteral(buf, relname.data);
2513 84 : appendStringInfo(buf, "::pg_catalog.regclass) / %d", BLCKSZ);
2514 84 : }
2515 :
2516 : /*
2517 : * Construct SELECT statement to acquire the number of rows and the relkind of
2518 : * a relation.
2519 : *
2520 : * Note: we just return the remote server's reltuples value, which might
2521 : * be off a good deal, but it doesn't seem worth working harder. See
2522 : * comments in postgresAcquireSampleRowsFunc.
2523 : */
2524 : void
2525 84 : deparseAnalyzeInfoSql(StringInfo buf, Relation rel)
2526 : {
2527 : StringInfoData relname;
2528 :
2529 : /* We'll need the remote relation name as a literal. */
2530 84 : initStringInfo(&relname);
2531 84 : deparseRelation(&relname, rel);
2532 :
2533 84 : appendStringInfoString(buf, "SELECT reltuples, relkind FROM pg_catalog.pg_class WHERE oid = ");
2534 84 : deparseStringLiteral(buf, relname.data);
2535 84 : appendStringInfoString(buf, "::pg_catalog.regclass");
2536 84 : }
2537 :
2538 : /*
2539 : * Construct SELECT statement to acquire sample rows of given relation.
2540 : *
2541 : * SELECT command is appended to buf, and list of columns retrieved
2542 : * is returned to *retrieved_attrs.
2543 : *
2544 : * We only support sampling methods we can decide based on server version.
2545 : * Allowing custom TSM modules (like tsm_system_rows) might be useful, but it
2546 : * would require detecting which extensions are installed, to allow automatic
2547 : * fall-back. Moreover, the methods may use different parameters like number
2548 : * of rows (and not sampling rate). So we leave this for future improvements.
2549 : *
2550 : * Using random() to sample rows on the remote server has the advantage that
2551 : * this works on all PostgreSQL versions (unlike TABLESAMPLE), and that it
2552 : * does the sampling on the remote side (without transferring everything and
2553 : * then discarding most rows).
2554 : *
2555 : * The disadvantage is that we still have to read all rows and evaluate the
2556 : * random(), while TABLESAMPLE (at least with the "system" method) may skip.
2557 : * It's not that different from the "bernoulli" method, though.
2558 : *
2559 : * We could also do "ORDER BY random() LIMIT x", which would always pick
2560 : * the expected number of rows, but it requires sorting so it may be much
2561 : * more expensive (particularly on large tables, which is what the
2562 : * remote sampling is meant to improve).
2563 : */
2564 : void
2565 84 : deparseAnalyzeSql(StringInfo buf, Relation rel,
2566 : PgFdwSamplingMethod sample_method, double sample_frac,
2567 : List **retrieved_attrs)
2568 : {
2569 84 : Oid relid = RelationGetRelid(rel);
2570 84 : TupleDesc tupdesc = RelationGetDescr(rel);
2571 : int i;
2572 : char *colname;
2573 : List *options;
2574 : ListCell *lc;
2575 84 : bool first = true;
2576 :
2577 84 : *retrieved_attrs = NIL;
2578 :
2579 84 : appendStringInfoString(buf, "SELECT ");
2580 364 : for (i = 0; i < tupdesc->natts; i++)
2581 : {
2582 : /* Ignore dropped columns. */
2583 280 : if (TupleDescAttr(tupdesc, i)->attisdropped)
2584 6 : continue;
2585 :
2586 274 : if (!first)
2587 190 : appendStringInfoString(buf, ", ");
2588 274 : first = false;
2589 :
2590 : /* Use attribute name or column_name option. */
2591 274 : colname = NameStr(TupleDescAttr(tupdesc, i)->attname);
2592 274 : options = GetForeignColumnOptions(relid, i + 1);
2593 :
2594 274 : foreach(lc, options)
2595 : {
2596 6 : DefElem *def = (DefElem *) lfirst(lc);
2597 :
2598 6 : if (strcmp(def->defname, "column_name") == 0)
2599 : {
2600 6 : colname = defGetString(def);
2601 6 : break;
2602 : }
2603 : }
2604 :
2605 274 : appendStringInfoString(buf, quote_identifier(colname));
2606 :
2607 274 : *retrieved_attrs = lappend_int(*retrieved_attrs, i + 1);
2608 : }
2609 :
2610 : /* Don't generate bad syntax for zero-column relation. */
2611 84 : if (first)
2612 0 : appendStringInfoString(buf, "NULL");
2613 :
2614 : /*
2615 : * Construct FROM clause, and perhaps WHERE clause too, depending on the
2616 : * selected sampling method.
2617 : */
2618 84 : appendStringInfoString(buf, " FROM ");
2619 84 : deparseRelation(buf, rel);
2620 :
2621 84 : switch (sample_method)
2622 : {
2623 84 : case ANALYZE_SAMPLE_OFF:
2624 : /* nothing to do here */
2625 84 : break;
2626 :
2627 0 : case ANALYZE_SAMPLE_RANDOM:
2628 0 : appendStringInfo(buf, " WHERE pg_catalog.random() < %f", sample_frac);
2629 0 : break;
2630 :
2631 0 : case ANALYZE_SAMPLE_SYSTEM:
2632 0 : appendStringInfo(buf, " TABLESAMPLE SYSTEM(%f)", (100.0 * sample_frac));
2633 0 : break;
2634 :
2635 0 : case ANALYZE_SAMPLE_BERNOULLI:
2636 0 : appendStringInfo(buf, " TABLESAMPLE BERNOULLI(%f)", (100.0 * sample_frac));
2637 0 : break;
2638 :
2639 0 : case ANALYZE_SAMPLE_AUTO:
2640 : /* should have been resolved into actual method */
2641 0 : elog(ERROR, "unexpected sampling method");
2642 : break;
2643 : }
2644 84 : }
2645 :
2646 : /*
2647 : * Construct a simple "TRUNCATE rel" statement
2648 : */
2649 : void
2650 24 : deparseTruncateSql(StringInfo buf,
2651 : List *rels,
2652 : DropBehavior behavior,
2653 : bool restart_seqs)
2654 : {
2655 : ListCell *cell;
2656 :
2657 24 : appendStringInfoString(buf, "TRUNCATE ");
2658 :
2659 52 : foreach(cell, rels)
2660 : {
2661 28 : Relation rel = lfirst(cell);
2662 :
2663 28 : if (cell != list_head(rels))
2664 4 : appendStringInfoString(buf, ", ");
2665 :
2666 28 : deparseRelation(buf, rel);
2667 : }
2668 :
2669 24 : appendStringInfo(buf, " %s IDENTITY",
2670 : restart_seqs ? "RESTART" : "CONTINUE");
2671 :
2672 24 : if (behavior == DROP_RESTRICT)
2673 20 : appendStringInfoString(buf, " RESTRICT");
2674 4 : else if (behavior == DROP_CASCADE)
2675 4 : appendStringInfoString(buf, " CASCADE");
2676 24 : }
2677 :
2678 : /*
2679 : * Construct name to use for given column, and emit it into buf.
2680 : * If it has a column_name FDW option, use that instead of attribute name.
2681 : *
2682 : * If qualify_col is true, qualify column name with the alias of relation.
2683 : */
2684 : static void
2685 30548 : deparseColumnRef(StringInfo buf, int varno, int varattno, RangeTblEntry *rte,
2686 : bool qualify_col)
2687 : {
2688 : /* We support fetching the remote side's CTID and OID. */
2689 30548 : if (varattno == SelfItemPointerAttributeNumber)
2690 : {
2691 120 : if (qualify_col)
2692 116 : ADD_REL_QUALIFIER(buf, varno);
2693 120 : appendStringInfoString(buf, "ctid");
2694 : }
2695 30428 : else if (varattno < 0)
2696 : {
2697 : /*
2698 : * All other system attributes are fetched as 0, except for table OID,
2699 : * which is fetched as the local table OID. However, we must be
2700 : * careful; the table could be beneath an outer join, in which case it
2701 : * must go to NULL whenever the rest of the row does.
2702 : */
2703 0 : Oid fetchval = 0;
2704 :
2705 0 : if (varattno == TableOidAttributeNumber)
2706 0 : fetchval = rte->relid;
2707 :
2708 0 : if (qualify_col)
2709 : {
2710 0 : appendStringInfoString(buf, "CASE WHEN (");
2711 0 : ADD_REL_QUALIFIER(buf, varno);
2712 0 : appendStringInfo(buf, "*)::text IS NOT NULL THEN %u END", fetchval);
2713 : }
2714 : else
2715 0 : appendStringInfo(buf, "%u", fetchval);
2716 : }
2717 30428 : else if (varattno == 0)
2718 : {
2719 : /* Whole row reference */
2720 : Relation rel;
2721 : Bitmapset *attrs_used;
2722 :
2723 : /* Required only to be passed down to deparseTargetList(). */
2724 : List *retrieved_attrs;
2725 :
2726 : /*
2727 : * The lock on the relation will be held by upper callers, so it's
2728 : * fine to open it with no lock here.
2729 : */
2730 532 : rel = table_open(rte->relid, NoLock);
2731 :
2732 : /*
2733 : * The local name of the foreign table can not be recognized by the
2734 : * foreign server and the table it references on foreign server might
2735 : * have different column ordering or different columns than those
2736 : * declared locally. Hence we have to deparse whole-row reference as
2737 : * ROW(columns referenced locally). Construct this by deparsing a
2738 : * "whole row" attribute.
2739 : */
2740 532 : attrs_used = bms_add_member(NULL,
2741 : 0 - FirstLowInvalidHeapAttributeNumber);
2742 :
2743 : /*
2744 : * In case the whole-row reference is under an outer join then it has
2745 : * to go NULL whenever the rest of the row goes NULL. Deparsing a join
2746 : * query would always involve multiple relations, thus qualify_col
2747 : * would be true.
2748 : */
2749 532 : if (qualify_col)
2750 : {
2751 524 : appendStringInfoString(buf, "CASE WHEN (");
2752 524 : ADD_REL_QUALIFIER(buf, varno);
2753 524 : appendStringInfoString(buf, "*)::text IS NOT NULL THEN ");
2754 : }
2755 :
2756 532 : appendStringInfoString(buf, "ROW(");
2757 532 : deparseTargetList(buf, rte, varno, rel, false, attrs_used, qualify_col,
2758 : &retrieved_attrs);
2759 532 : appendStringInfoChar(buf, ')');
2760 :
2761 : /* Complete the CASE WHEN statement started above. */
2762 532 : if (qualify_col)
2763 524 : appendStringInfoString(buf, " END");
2764 :
2765 532 : table_close(rel, NoLock);
2766 532 : bms_free(attrs_used);
2767 : }
2768 : else
2769 : {
2770 29896 : char *colname = NULL;
2771 : List *options;
2772 : ListCell *lc;
2773 :
2774 : /* varno must not be any of OUTER_VAR, INNER_VAR and INDEX_VAR. */
2775 : Assert(!IS_SPECIAL_VARNO(varno));
2776 :
2777 : /*
2778 : * If it's a column of a foreign table, and it has the column_name FDW
2779 : * option, use that value.
2780 : */
2781 29896 : options = GetForeignColumnOptions(rte->relid, varattno);
2782 29896 : foreach(lc, options)
2783 : {
2784 6934 : DefElem *def = (DefElem *) lfirst(lc);
2785 :
2786 6934 : if (strcmp(def->defname, "column_name") == 0)
2787 : {
2788 6934 : colname = defGetString(def);
2789 6934 : break;
2790 : }
2791 : }
2792 :
2793 : /*
2794 : * If it's a column of a regular table or it doesn't have column_name
2795 : * FDW option, use attribute name.
2796 : */
2797 29896 : if (colname == NULL)
2798 22962 : colname = get_attname(rte->relid, varattno, false);
2799 :
2800 29896 : if (qualify_col)
2801 15448 : ADD_REL_QUALIFIER(buf, varno);
2802 :
2803 29896 : appendStringInfoString(buf, quote_identifier(colname));
2804 : }
2805 30548 : }
2806 :
2807 : /*
2808 : * Append remote name of specified foreign table to buf.
2809 : * Use value of table_name FDW option (if any) instead of relation's name.
2810 : * Similarly, schema_name FDW option overrides schema name.
2811 : */
2812 : static void
2813 7370 : deparseRelation(StringInfo buf, Relation rel)
2814 : {
2815 : ForeignTable *table;
2816 7370 : const char *nspname = NULL;
2817 7370 : const char *relname = NULL;
2818 : ListCell *lc;
2819 :
2820 : /* obtain additional catalog information. */
2821 7370 : table = GetForeignTable(RelationGetRelid(rel));
2822 :
2823 : /*
2824 : * Use value of FDW options if any, instead of the name of object itself.
2825 : */
2826 24242 : foreach(lc, table->options)
2827 : {
2828 16872 : DefElem *def = (DefElem *) lfirst(lc);
2829 :
2830 16872 : if (strcmp(def->defname, "schema_name") == 0)
2831 5150 : nspname = defGetString(def);
2832 11722 : else if (strcmp(def->defname, "table_name") == 0)
2833 7370 : relname = defGetString(def);
2834 : }
2835 :
2836 : /*
2837 : * Note: we could skip printing the schema name if it's pg_catalog, but
2838 : * that doesn't seem worth the trouble.
2839 : */
2840 7370 : if (nspname == NULL)
2841 2220 : nspname = get_namespace_name(RelationGetNamespace(rel));
2842 7370 : if (relname == NULL)
2843 0 : relname = RelationGetRelationName(rel);
2844 :
2845 7370 : appendStringInfo(buf, "%s.%s",
2846 : quote_identifier(nspname), quote_identifier(relname));
2847 7370 : }
2848 :
2849 : /*
2850 : * Append a SQL string literal representing "val" to buf.
2851 : */
2852 : void
2853 680 : deparseStringLiteral(StringInfo buf, const char *val)
2854 : {
2855 : const char *valptr;
2856 :
2857 : /*
2858 : * Rather than making assumptions about the remote server's value of
2859 : * standard_conforming_strings, always use E'foo' syntax if there are any
2860 : * backslashes. This will fail on remote servers before 8.1, but those
2861 : * are long out of support.
2862 : */
2863 680 : if (strchr(val, '\\') != NULL)
2864 2 : appendStringInfoChar(buf, ESCAPE_STRING_SYNTAX);
2865 680 : appendStringInfoChar(buf, '\'');
2866 6104 : for (valptr = val; *valptr; valptr++)
2867 : {
2868 5424 : char ch = *valptr;
2869 :
2870 5424 : if (SQL_STR_DOUBLE(ch, true))
2871 4 : appendStringInfoChar(buf, ch);
2872 5424 : appendStringInfoChar(buf, ch);
2873 : }
2874 680 : appendStringInfoChar(buf, '\'');
2875 680 : }
2876 :
2877 : /*
2878 : * Deparse given expression into context->buf.
2879 : *
2880 : * This function must support all the same node types that foreign_expr_walker
2881 : * accepts.
2882 : *
2883 : * Note: unlike ruleutils.c, we just use a simple hard-wired parenthesization
2884 : * scheme: anything more complex than a Var, Const, function call or cast
2885 : * should be self-parenthesized.
2886 : */
2887 : static void
2888 24892 : deparseExpr(Expr *node, deparse_expr_cxt *context)
2889 : {
2890 24892 : if (node == NULL)
2891 0 : return;
2892 :
2893 24892 : switch (nodeTag(node))
2894 : {
2895 17210 : case T_Var:
2896 17210 : deparseVar((Var *) node, context);
2897 17210 : break;
2898 1172 : case T_Const:
2899 1172 : deparseConst((Const *) node, context, 0);
2900 1172 : break;
2901 56 : case T_Param:
2902 56 : deparseParam((Param *) node, context);
2903 56 : break;
2904 2 : case T_SubscriptingRef:
2905 2 : deparseSubscriptingRef((SubscriptingRef *) node, context);
2906 2 : break;
2907 116 : case T_FuncExpr:
2908 116 : deparseFuncExpr((FuncExpr *) node, context);
2909 116 : break;
2910 5554 : case T_OpExpr:
2911 5554 : deparseOpExpr((OpExpr *) node, context);
2912 5554 : break;
2913 2 : case T_DistinctExpr:
2914 2 : deparseDistinctExpr((DistinctExpr *) node, context);
2915 2 : break;
2916 8 : case T_ScalarArrayOpExpr:
2917 8 : deparseScalarArrayOpExpr((ScalarArrayOpExpr *) node, context);
2918 8 : break;
2919 66 : case T_RelabelType:
2920 66 : deparseRelabelType((RelabelType *) node, context);
2921 66 : break;
2922 76 : case T_BoolExpr:
2923 76 : deparseBoolExpr((BoolExpr *) node, context);
2924 76 : break;
2925 56 : case T_NullTest:
2926 56 : deparseNullTest((NullTest *) node, context);
2927 56 : break;
2928 42 : case T_CaseExpr:
2929 42 : deparseCaseExpr((CaseExpr *) node, context);
2930 42 : break;
2931 8 : case T_ArrayExpr:
2932 8 : deparseArrayExpr((ArrayExpr *) node, context);
2933 8 : break;
2934 524 : case T_Aggref:
2935 524 : deparseAggref((Aggref *) node, context);
2936 524 : break;
2937 0 : default:
2938 0 : elog(ERROR, "unsupported expression type for deparse: %d",
2939 : (int) nodeTag(node));
2940 : break;
2941 : }
2942 : }
2943 :
2944 : /*
2945 : * Deparse given Var node into context->buf.
2946 : *
2947 : * If the Var belongs to the foreign relation, just print its remote name.
2948 : * Otherwise, it's effectively a Param (and will in fact be a Param at
2949 : * run time). Handle it the same way we handle plain Params --- see
2950 : * deparseParam for comments.
2951 : */
2952 : static void
2953 17210 : deparseVar(Var *node, deparse_expr_cxt *context)
2954 : {
2955 17210 : Relids relids = context->scanrel->relids;
2956 : int relno;
2957 : int colno;
2958 :
2959 : /* Qualify columns when multiple relations are involved. */
2960 17210 : bool qualify_col = (bms_membership(relids) == BMS_MULTIPLE);
2961 :
2962 : /*
2963 : * If the Var belongs to the foreign relation that is deparsed as a
2964 : * subquery, use the relation and column alias to the Var provided by the
2965 : * subquery, instead of the remote name.
2966 : */
2967 17210 : if (is_subquery_var(node, context->scanrel, &relno, &colno))
2968 : {
2969 304 : appendStringInfo(context->buf, "%s%d.%s%d",
2970 : SUBQUERY_REL_ALIAS_PREFIX, relno,
2971 : SUBQUERY_COL_ALIAS_PREFIX, colno);
2972 304 : return;
2973 : }
2974 :
2975 16906 : if (bms_is_member(node->varno, relids) && node->varlevelsup == 0)
2976 16476 : deparseColumnRef(context->buf, node->varno, node->varattno,
2977 16476 : planner_rt_fetch(node->varno, context->root),
2978 : qualify_col);
2979 : else
2980 : {
2981 : /* Treat like a Param */
2982 430 : if (context->params_list)
2983 : {
2984 22 : int pindex = 0;
2985 : ListCell *lc;
2986 :
2987 : /* find its index in params_list */
2988 22 : foreach(lc, *context->params_list)
2989 : {
2990 0 : pindex++;
2991 0 : if (equal(node, (Node *) lfirst(lc)))
2992 0 : break;
2993 : }
2994 22 : if (lc == NULL)
2995 : {
2996 : /* not in list, so add it */
2997 22 : pindex++;
2998 22 : *context->params_list = lappend(*context->params_list, node);
2999 : }
3000 :
3001 22 : printRemoteParam(pindex, node->vartype, node->vartypmod, context);
3002 : }
3003 : else
3004 : {
3005 408 : printRemotePlaceholder(node->vartype, node->vartypmod, context);
3006 : }
3007 : }
3008 : }
3009 :
3010 : /*
3011 : * Deparse given constant value into context->buf.
3012 : *
3013 : * This function has to be kept in sync with ruleutils.c's get_const_expr.
3014 : *
3015 : * As in that function, showtype can be -1 to never show "::typename"
3016 : * decoration, +1 to always show it, or 0 to show it only if the constant
3017 : * wouldn't be assumed to be the right type by default.
3018 : *
3019 : * In addition, this code allows showtype to be -2 to indicate that we should
3020 : * not show "::typename" decoration if the constant is printed as an untyped
3021 : * literal or NULL (while in other cases, behaving as for showtype == 0).
3022 : */
3023 : static void
3024 3748 : deparseConst(Const *node, deparse_expr_cxt *context, int showtype)
3025 : {
3026 3748 : StringInfo buf = context->buf;
3027 : Oid typoutput;
3028 : bool typIsVarlena;
3029 : char *extval;
3030 3748 : bool isfloat = false;
3031 3748 : bool isstring = false;
3032 : bool needlabel;
3033 :
3034 3748 : if (node->constisnull)
3035 : {
3036 38 : appendStringInfoString(buf, "NULL");
3037 38 : if (showtype >= 0)
3038 38 : appendStringInfo(buf, "::%s",
3039 : deparse_type_name(node->consttype,
3040 : node->consttypmod));
3041 38 : return;
3042 : }
3043 :
3044 3710 : getTypeOutputInfo(node->consttype,
3045 : &typoutput, &typIsVarlena);
3046 3710 : extval = OidOutputFunctionCall(typoutput, node->constvalue);
3047 :
3048 3710 : switch (node->consttype)
3049 : {
3050 3544 : case INT2OID:
3051 : case INT4OID:
3052 : case INT8OID:
3053 : case OIDOID:
3054 : case FLOAT4OID:
3055 : case FLOAT8OID:
3056 : case NUMERICOID:
3057 : {
3058 : /*
3059 : * No need to quote unless it's a special value such as 'NaN'.
3060 : * See comments in get_const_expr().
3061 : */
3062 3544 : if (strspn(extval, "0123456789+-eE.") == strlen(extval))
3063 : {
3064 3544 : if (extval[0] == '+' || extval[0] == '-')
3065 2 : appendStringInfo(buf, "(%s)", extval);
3066 : else
3067 3542 : appendStringInfoString(buf, extval);
3068 3544 : if (strcspn(extval, "eE.") != strlen(extval))
3069 4 : isfloat = true; /* it looks like a float */
3070 : }
3071 : else
3072 0 : appendStringInfo(buf, "'%s'", extval);
3073 : }
3074 3544 : break;
3075 0 : case BITOID:
3076 : case VARBITOID:
3077 0 : appendStringInfo(buf, "B'%s'", extval);
3078 0 : break;
3079 4 : case BOOLOID:
3080 4 : if (strcmp(extval, "t") == 0)
3081 4 : appendStringInfoString(buf, "true");
3082 : else
3083 0 : appendStringInfoString(buf, "false");
3084 4 : break;
3085 162 : default:
3086 162 : deparseStringLiteral(buf, extval);
3087 162 : isstring = true;
3088 162 : break;
3089 : }
3090 :
3091 3710 : pfree(extval);
3092 :
3093 3710 : if (showtype == -1)
3094 0 : return; /* never print type label */
3095 :
3096 : /*
3097 : * For showtype == 0, append ::typename unless the constant will be
3098 : * implicitly typed as the right type when it is read in.
3099 : *
3100 : * XXX this code has to be kept in sync with the behavior of the parser,
3101 : * especially make_const.
3102 : */
3103 3710 : switch (node->consttype)
3104 : {
3105 3060 : case BOOLOID:
3106 : case INT4OID:
3107 : case UNKNOWNOID:
3108 3060 : needlabel = false;
3109 3060 : break;
3110 42 : case NUMERICOID:
3111 42 : needlabel = !isfloat || (node->consttypmod >= 0);
3112 42 : break;
3113 608 : default:
3114 608 : if (showtype == -2)
3115 : {
3116 : /* label unless we printed it as an untyped string */
3117 86 : needlabel = !isstring;
3118 : }
3119 : else
3120 522 : needlabel = true;
3121 608 : break;
3122 : }
3123 3710 : if (needlabel || showtype > 0)
3124 560 : appendStringInfo(buf, "::%s",
3125 : deparse_type_name(node->consttype,
3126 : node->consttypmod));
3127 : }
3128 :
3129 : /*
3130 : * Deparse given Param node.
3131 : *
3132 : * If we're generating the query "for real", add the Param to
3133 : * context->params_list if it's not already present, and then use its index
3134 : * in that list as the remote parameter number. During EXPLAIN, there's
3135 : * no need to identify a parameter number.
3136 : */
3137 : static void
3138 56 : deparseParam(Param *node, deparse_expr_cxt *context)
3139 : {
3140 56 : if (context->params_list)
3141 : {
3142 36 : int pindex = 0;
3143 : ListCell *lc;
3144 :
3145 : /* find its index in params_list */
3146 40 : foreach(lc, *context->params_list)
3147 : {
3148 4 : pindex++;
3149 4 : if (equal(node, (Node *) lfirst(lc)))
3150 0 : break;
3151 : }
3152 36 : if (lc == NULL)
3153 : {
3154 : /* not in list, so add it */
3155 36 : pindex++;
3156 36 : *context->params_list = lappend(*context->params_list, node);
3157 : }
3158 :
3159 36 : printRemoteParam(pindex, node->paramtype, node->paramtypmod, context);
3160 : }
3161 : else
3162 : {
3163 20 : printRemotePlaceholder(node->paramtype, node->paramtypmod, context);
3164 : }
3165 56 : }
3166 :
3167 : /*
3168 : * Deparse a container subscript expression.
3169 : */
3170 : static void
3171 2 : deparseSubscriptingRef(SubscriptingRef *node, deparse_expr_cxt *context)
3172 : {
3173 2 : StringInfo buf = context->buf;
3174 : ListCell *lowlist_item;
3175 : ListCell *uplist_item;
3176 :
3177 : /* Always parenthesize the expression. */
3178 2 : appendStringInfoChar(buf, '(');
3179 :
3180 : /*
3181 : * Deparse referenced array expression first. If that expression includes
3182 : * a cast, we have to parenthesize to prevent the array subscript from
3183 : * being taken as typename decoration. We can avoid that in the typical
3184 : * case of subscripting a Var, but otherwise do it.
3185 : */
3186 2 : if (IsA(node->refexpr, Var))
3187 0 : deparseExpr(node->refexpr, context);
3188 : else
3189 : {
3190 2 : appendStringInfoChar(buf, '(');
3191 2 : deparseExpr(node->refexpr, context);
3192 2 : appendStringInfoChar(buf, ')');
3193 : }
3194 :
3195 : /* Deparse subscript expressions. */
3196 2 : lowlist_item = list_head(node->reflowerindexpr); /* could be NULL */
3197 4 : foreach(uplist_item, node->refupperindexpr)
3198 : {
3199 2 : appendStringInfoChar(buf, '[');
3200 2 : if (lowlist_item)
3201 : {
3202 0 : deparseExpr(lfirst(lowlist_item), context);
3203 0 : appendStringInfoChar(buf, ':');
3204 0 : lowlist_item = lnext(node->reflowerindexpr, lowlist_item);
3205 : }
3206 2 : deparseExpr(lfirst(uplist_item), context);
3207 2 : appendStringInfoChar(buf, ']');
3208 : }
3209 :
3210 2 : appendStringInfoChar(buf, ')');
3211 2 : }
3212 :
3213 : /*
3214 : * Deparse a function call.
3215 : */
3216 : static void
3217 116 : deparseFuncExpr(FuncExpr *node, deparse_expr_cxt *context)
3218 : {
3219 116 : StringInfo buf = context->buf;
3220 : bool use_variadic;
3221 : bool first;
3222 : ListCell *arg;
3223 :
3224 : /*
3225 : * If the function call came from an implicit coercion, then just show the
3226 : * first argument.
3227 : */
3228 116 : if (node->funcformat == COERCE_IMPLICIT_CAST)
3229 : {
3230 42 : deparseExpr((Expr *) linitial(node->args), context);
3231 42 : return;
3232 : }
3233 :
3234 : /*
3235 : * If the function call came from a cast, then show the first argument
3236 : * plus an explicit cast operation.
3237 : */
3238 74 : if (node->funcformat == COERCE_EXPLICIT_CAST)
3239 : {
3240 0 : Oid rettype = node->funcresulttype;
3241 : int32 coercedTypmod;
3242 :
3243 : /* Get the typmod if this is a length-coercion function */
3244 0 : (void) exprIsLengthCoercion((Node *) node, &coercedTypmod);
3245 :
3246 0 : deparseExpr((Expr *) linitial(node->args), context);
3247 0 : appendStringInfo(buf, "::%s",
3248 : deparse_type_name(rettype, coercedTypmod));
3249 0 : return;
3250 : }
3251 :
3252 : /* Check if need to print VARIADIC (cf. ruleutils.c) */
3253 74 : use_variadic = node->funcvariadic;
3254 :
3255 : /*
3256 : * Normal function: display as proname(args).
3257 : */
3258 74 : appendFunctionName(node->funcid, context);
3259 74 : appendStringInfoChar(buf, '(');
3260 :
3261 : /* ... and all the arguments */
3262 74 : first = true;
3263 156 : foreach(arg, node->args)
3264 : {
3265 82 : if (!first)
3266 8 : appendStringInfoString(buf, ", ");
3267 82 : if (use_variadic && lnext(node->args, arg) == NULL)
3268 0 : appendStringInfoString(buf, "VARIADIC ");
3269 82 : deparseExpr((Expr *) lfirst(arg), context);
3270 82 : first = false;
3271 : }
3272 74 : appendStringInfoChar(buf, ')');
3273 : }
3274 :
3275 : /*
3276 : * Deparse given operator expression. To avoid problems around
3277 : * priority of operations, we always parenthesize the arguments.
3278 : */
3279 : static void
3280 5554 : deparseOpExpr(OpExpr *node, deparse_expr_cxt *context)
3281 : {
3282 5554 : StringInfo buf = context->buf;
3283 : HeapTuple tuple;
3284 : Form_pg_operator form;
3285 : Expr *right;
3286 5554 : bool canSuppressRightConstCast = false;
3287 : char oprkind;
3288 :
3289 : /* Retrieve information about the operator from system catalog. */
3290 5554 : tuple = SearchSysCache1(OPEROID, ObjectIdGetDatum(node->opno));
3291 5554 : if (!HeapTupleIsValid(tuple))
3292 0 : elog(ERROR, "cache lookup failed for operator %u", node->opno);
3293 5554 : form = (Form_pg_operator) GETSTRUCT(tuple);
3294 5554 : oprkind = form->oprkind;
3295 :
3296 : /* Sanity check. */
3297 : Assert((oprkind == 'l' && list_length(node->args) == 1) ||
3298 : (oprkind == 'b' && list_length(node->args) == 2));
3299 :
3300 5554 : right = llast(node->args);
3301 :
3302 : /* Always parenthesize the expression. */
3303 5554 : appendStringInfoChar(buf, '(');
3304 :
3305 : /* Deparse left operand, if any. */
3306 5554 : if (oprkind == 'b')
3307 : {
3308 5548 : Expr *left = linitial(node->args);
3309 5548 : Oid leftType = exprType((Node *) left);
3310 5548 : Oid rightType = exprType((Node *) right);
3311 5548 : bool canSuppressLeftConstCast = false;
3312 :
3313 : /*
3314 : * When considering a binary operator, if one operand is a Const that
3315 : * can be printed as a bare string literal or NULL (i.e., it will look
3316 : * like type UNKNOWN to the remote parser), the Const normally
3317 : * receives an explicit cast to the operator's input type. However,
3318 : * in Const-to-Var comparisons where both operands are of the same
3319 : * type, we prefer to suppress the explicit cast, leaving the Const's
3320 : * type resolution up to the remote parser. The remote's resolution
3321 : * heuristic will assume that an unknown input type being compared to
3322 : * a known input type is of that known type as well.
3323 : *
3324 : * This hack allows some cases to succeed where a remote column is
3325 : * declared with a different type in the local (foreign) table. By
3326 : * emitting "foreigncol = 'foo'" not "foreigncol = 'foo'::text" or the
3327 : * like, we allow the remote parser to pick an "=" operator that's
3328 : * compatible with whatever type the remote column really is, such as
3329 : * an enum.
3330 : *
3331 : * We allow cast suppression to happen only when the other operand is
3332 : * a plain foreign Var. Although the remote's unknown-type heuristic
3333 : * would apply to other cases just as well, we would be taking a
3334 : * bigger risk that the inferred type is something unexpected. With
3335 : * this restriction, if anything goes wrong it's the user's fault for
3336 : * not declaring the local column with the same type as the remote
3337 : * column.
3338 : */
3339 5548 : if (leftType == rightType)
3340 : {
3341 5516 : if (IsA(left, Const))
3342 6 : canSuppressLeftConstCast = isPlainForeignVar(right, context);
3343 5510 : else if (IsA(right, Const))
3344 3086 : canSuppressRightConstCast = isPlainForeignVar(left, context);
3345 : }
3346 :
3347 5548 : if (canSuppressLeftConstCast)
3348 4 : deparseConst((Const *) left, context, -2);
3349 : else
3350 5544 : deparseExpr(left, context);
3351 :
3352 5548 : appendStringInfoChar(buf, ' ');
3353 : }
3354 :
3355 : /* Deparse operator name. */
3356 5554 : deparseOperatorName(buf, form);
3357 :
3358 : /* Deparse right operand. */
3359 5554 : appendStringInfoChar(buf, ' ');
3360 :
3361 5554 : if (canSuppressRightConstCast)
3362 2572 : deparseConst((Const *) right, context, -2);
3363 : else
3364 2982 : deparseExpr(right, context);
3365 :
3366 5554 : appendStringInfoChar(buf, ')');
3367 :
3368 5554 : ReleaseSysCache(tuple);
3369 5554 : }
3370 :
3371 : /*
3372 : * Will "node" deparse as a plain foreign Var?
3373 : */
3374 : static bool
3375 3092 : isPlainForeignVar(Expr *node, deparse_expr_cxt *context)
3376 : {
3377 : /*
3378 : * We allow the foreign Var to have an implicit RelabelType, mainly so
3379 : * that this'll work with varchar columns. Note that deparseRelabelType
3380 : * will not print such a cast, so we're not breaking the restriction that
3381 : * the expression print as a plain Var. We won't risk it for an implicit
3382 : * cast that requires a function, nor for non-implicit RelabelType; such
3383 : * cases seem too likely to involve semantics changes compared to what
3384 : * would happen on the remote side.
3385 : */
3386 3092 : if (IsA(node, RelabelType) &&
3387 10 : ((RelabelType *) node)->relabelformat == COERCE_IMPLICIT_CAST)
3388 10 : node = ((RelabelType *) node)->arg;
3389 :
3390 3092 : if (IsA(node, Var))
3391 : {
3392 : /*
3393 : * The Var must be one that'll deparse as a foreign column reference
3394 : * (cf. deparseVar).
3395 : */
3396 2576 : Var *var = (Var *) node;
3397 2576 : Relids relids = context->scanrel->relids;
3398 :
3399 2576 : if (bms_is_member(var->varno, relids) && var->varlevelsup == 0)
3400 2576 : return true;
3401 : }
3402 :
3403 516 : return false;
3404 : }
3405 :
3406 : /*
3407 : * Print the name of an operator.
3408 : */
3409 : static void
3410 5578 : deparseOperatorName(StringInfo buf, Form_pg_operator opform)
3411 : {
3412 : char *opname;
3413 :
3414 : /* opname is not a SQL identifier, so we should not quote it. */
3415 5578 : opname = NameStr(opform->oprname);
3416 :
3417 : /* Print schema name only if it's not pg_catalog */
3418 5578 : if (opform->oprnamespace != PG_CATALOG_NAMESPACE)
3419 : {
3420 : const char *opnspname;
3421 :
3422 26 : opnspname = get_namespace_name(opform->oprnamespace);
3423 : /* Print fully qualified operator name. */
3424 26 : appendStringInfo(buf, "OPERATOR(%s.%s)",
3425 : quote_identifier(opnspname), opname);
3426 : }
3427 : else
3428 : {
3429 : /* Just print operator name. */
3430 5552 : appendStringInfoString(buf, opname);
3431 : }
3432 5578 : }
3433 :
3434 : /*
3435 : * Deparse IS DISTINCT FROM.
3436 : */
3437 : static void
3438 2 : deparseDistinctExpr(DistinctExpr *node, deparse_expr_cxt *context)
3439 : {
3440 2 : StringInfo buf = context->buf;
3441 :
3442 : Assert(list_length(node->args) == 2);
3443 :
3444 2 : appendStringInfoChar(buf, '(');
3445 2 : deparseExpr(linitial(node->args), context);
3446 2 : appendStringInfoString(buf, " IS DISTINCT FROM ");
3447 2 : deparseExpr(lsecond(node->args), context);
3448 2 : appendStringInfoChar(buf, ')');
3449 2 : }
3450 :
3451 : /*
3452 : * Deparse given ScalarArrayOpExpr expression. To avoid problems
3453 : * around priority of operations, we always parenthesize the arguments.
3454 : */
3455 : static void
3456 8 : deparseScalarArrayOpExpr(ScalarArrayOpExpr *node, deparse_expr_cxt *context)
3457 : {
3458 8 : StringInfo buf = context->buf;
3459 : HeapTuple tuple;
3460 : Form_pg_operator form;
3461 : Expr *arg1;
3462 : Expr *arg2;
3463 :
3464 : /* Retrieve information about the operator from system catalog. */
3465 8 : tuple = SearchSysCache1(OPEROID, ObjectIdGetDatum(node->opno));
3466 8 : if (!HeapTupleIsValid(tuple))
3467 0 : elog(ERROR, "cache lookup failed for operator %u", node->opno);
3468 8 : form = (Form_pg_operator) GETSTRUCT(tuple);
3469 :
3470 : /* Sanity check. */
3471 : Assert(list_length(node->args) == 2);
3472 :
3473 : /* Always parenthesize the expression. */
3474 8 : appendStringInfoChar(buf, '(');
3475 :
3476 : /* Deparse left operand. */
3477 8 : arg1 = linitial(node->args);
3478 8 : deparseExpr(arg1, context);
3479 8 : appendStringInfoChar(buf, ' ');
3480 :
3481 : /* Deparse operator name plus decoration. */
3482 8 : deparseOperatorName(buf, form);
3483 8 : appendStringInfo(buf, " %s (", node->useOr ? "ANY" : "ALL");
3484 :
3485 : /* Deparse right operand. */
3486 8 : arg2 = lsecond(node->args);
3487 8 : deparseExpr(arg2, context);
3488 :
3489 8 : appendStringInfoChar(buf, ')');
3490 :
3491 : /* Always parenthesize the expression. */
3492 8 : appendStringInfoChar(buf, ')');
3493 :
3494 8 : ReleaseSysCache(tuple);
3495 8 : }
3496 :
3497 : /*
3498 : * Deparse a RelabelType (binary-compatible cast) node.
3499 : */
3500 : static void
3501 66 : deparseRelabelType(RelabelType *node, deparse_expr_cxt *context)
3502 : {
3503 66 : deparseExpr(node->arg, context);
3504 66 : if (node->relabelformat != COERCE_IMPLICIT_CAST)
3505 0 : appendStringInfo(context->buf, "::%s",
3506 : deparse_type_name(node->resulttype,
3507 : node->resulttypmod));
3508 66 : }
3509 :
3510 : /*
3511 : * Deparse a BoolExpr node.
3512 : */
3513 : static void
3514 76 : deparseBoolExpr(BoolExpr *node, deparse_expr_cxt *context)
3515 : {
3516 76 : StringInfo buf = context->buf;
3517 76 : const char *op = NULL; /* keep compiler quiet */
3518 : bool first;
3519 : ListCell *lc;
3520 :
3521 76 : switch (node->boolop)
3522 : {
3523 36 : case AND_EXPR:
3524 36 : op = "AND";
3525 36 : break;
3526 40 : case OR_EXPR:
3527 40 : op = "OR";
3528 40 : break;
3529 0 : case NOT_EXPR:
3530 0 : appendStringInfoString(buf, "(NOT ");
3531 0 : deparseExpr(linitial(node->args), context);
3532 0 : appendStringInfoChar(buf, ')');
3533 0 : return;
3534 : }
3535 :
3536 76 : appendStringInfoChar(buf, '(');
3537 76 : first = true;
3538 228 : foreach(lc, node->args)
3539 : {
3540 152 : if (!first)
3541 76 : appendStringInfo(buf, " %s ", op);
3542 152 : deparseExpr((Expr *) lfirst(lc), context);
3543 152 : first = false;
3544 : }
3545 76 : appendStringInfoChar(buf, ')');
3546 : }
3547 :
3548 : /*
3549 : * Deparse IS [NOT] NULL expression.
3550 : */
3551 : static void
3552 56 : deparseNullTest(NullTest *node, deparse_expr_cxt *context)
3553 : {
3554 56 : StringInfo buf = context->buf;
3555 :
3556 56 : appendStringInfoChar(buf, '(');
3557 56 : deparseExpr(node->arg, context);
3558 :
3559 : /*
3560 : * For scalar inputs, we prefer to print as IS [NOT] NULL, which is
3561 : * shorter and traditional. If it's a rowtype input but we're applying a
3562 : * scalar test, must print IS [NOT] DISTINCT FROM NULL to be semantically
3563 : * correct.
3564 : */
3565 56 : if (node->argisrow || !type_is_rowtype(exprType((Node *) node->arg)))
3566 : {
3567 56 : if (node->nulltesttype == IS_NULL)
3568 38 : appendStringInfoString(buf, " IS NULL)");
3569 : else
3570 18 : appendStringInfoString(buf, " IS NOT NULL)");
3571 : }
3572 : else
3573 : {
3574 0 : if (node->nulltesttype == IS_NULL)
3575 0 : appendStringInfoString(buf, " IS NOT DISTINCT FROM NULL)");
3576 : else
3577 0 : appendStringInfoString(buf, " IS DISTINCT FROM NULL)");
3578 : }
3579 56 : }
3580 :
3581 : /*
3582 : * Deparse CASE expression
3583 : */
3584 : static void
3585 42 : deparseCaseExpr(CaseExpr *node, deparse_expr_cxt *context)
3586 : {
3587 42 : StringInfo buf = context->buf;
3588 : ListCell *lc;
3589 :
3590 42 : appendStringInfoString(buf, "(CASE");
3591 :
3592 : /* If this is a CASE arg WHEN then emit the arg expression */
3593 42 : if (node->arg != NULL)
3594 : {
3595 18 : appendStringInfoChar(buf, ' ');
3596 18 : deparseExpr(node->arg, context);
3597 : }
3598 :
3599 : /* Add each condition/result of the CASE clause */
3600 98 : foreach(lc, node->args)
3601 : {
3602 56 : CaseWhen *whenclause = (CaseWhen *) lfirst(lc);
3603 :
3604 : /* WHEN */
3605 56 : appendStringInfoString(buf, " WHEN ");
3606 56 : if (node->arg == NULL) /* CASE WHEN */
3607 24 : deparseExpr(whenclause->expr, context);
3608 : else /* CASE arg WHEN */
3609 : {
3610 : /* Ignore the CaseTestExpr and equality operator. */
3611 32 : deparseExpr(lsecond(castNode(OpExpr, whenclause->expr)->args),
3612 : context);
3613 : }
3614 :
3615 : /* THEN */
3616 56 : appendStringInfoString(buf, " THEN ");
3617 56 : deparseExpr(whenclause->result, context);
3618 : }
3619 :
3620 : /* add ELSE if present */
3621 42 : if (node->defresult != NULL)
3622 : {
3623 42 : appendStringInfoString(buf, " ELSE ");
3624 42 : deparseExpr(node->defresult, context);
3625 : }
3626 :
3627 : /* append END */
3628 42 : appendStringInfoString(buf, " END)");
3629 42 : }
3630 :
3631 : /*
3632 : * Deparse ARRAY[...] construct.
3633 : */
3634 : static void
3635 8 : deparseArrayExpr(ArrayExpr *node, deparse_expr_cxt *context)
3636 : {
3637 8 : StringInfo buf = context->buf;
3638 8 : bool first = true;
3639 : ListCell *lc;
3640 :
3641 8 : appendStringInfoString(buf, "ARRAY[");
3642 24 : foreach(lc, node->elements)
3643 : {
3644 16 : if (!first)
3645 8 : appendStringInfoString(buf, ", ");
3646 16 : deparseExpr(lfirst(lc), context);
3647 16 : first = false;
3648 : }
3649 8 : appendStringInfoChar(buf, ']');
3650 :
3651 : /* If the array is empty, we need an explicit cast to the array type. */
3652 8 : if (node->elements == NIL)
3653 0 : appendStringInfo(buf, "::%s",
3654 : deparse_type_name(node->array_typeid, -1));
3655 8 : }
3656 :
3657 : /*
3658 : * Deparse an Aggref node.
3659 : */
3660 : static void
3661 524 : deparseAggref(Aggref *node, deparse_expr_cxt *context)
3662 : {
3663 524 : StringInfo buf = context->buf;
3664 : bool use_variadic;
3665 :
3666 : /* Only basic, non-split aggregation accepted. */
3667 : Assert(node->aggsplit == AGGSPLIT_SIMPLE);
3668 :
3669 : /* Check if need to print VARIADIC (cf. ruleutils.c) */
3670 524 : use_variadic = node->aggvariadic;
3671 :
3672 : /* Find aggregate name from aggfnoid which is a pg_proc entry */
3673 524 : appendFunctionName(node->aggfnoid, context);
3674 524 : appendStringInfoChar(buf, '(');
3675 :
3676 : /* Add DISTINCT */
3677 524 : appendStringInfoString(buf, (node->aggdistinct != NIL) ? "DISTINCT " : "");
3678 :
3679 524 : if (AGGKIND_IS_ORDERED_SET(node->aggkind))
3680 : {
3681 : /* Add WITHIN GROUP (ORDER BY ..) */
3682 : ListCell *arg;
3683 16 : bool first = true;
3684 :
3685 : Assert(!node->aggvariadic);
3686 : Assert(node->aggorder != NIL);
3687 :
3688 36 : foreach(arg, node->aggdirectargs)
3689 : {
3690 20 : if (!first)
3691 4 : appendStringInfoString(buf, ", ");
3692 20 : first = false;
3693 :
3694 20 : deparseExpr((Expr *) lfirst(arg), context);
3695 : }
3696 :
3697 16 : appendStringInfoString(buf, ") WITHIN GROUP (ORDER BY ");
3698 16 : appendAggOrderBy(node->aggorder, node->args, context);
3699 : }
3700 : else
3701 : {
3702 : /* aggstar can be set only in zero-argument aggregates */
3703 508 : if (node->aggstar)
3704 136 : appendStringInfoChar(buf, '*');
3705 : else
3706 : {
3707 : ListCell *arg;
3708 372 : bool first = true;
3709 :
3710 : /* Add all the arguments */
3711 752 : foreach(arg, node->args)
3712 : {
3713 380 : TargetEntry *tle = (TargetEntry *) lfirst(arg);
3714 380 : Node *n = (Node *) tle->expr;
3715 :
3716 380 : if (tle->resjunk)
3717 8 : continue;
3718 :
3719 372 : if (!first)
3720 0 : appendStringInfoString(buf, ", ");
3721 372 : first = false;
3722 :
3723 : /* Add VARIADIC */
3724 372 : if (use_variadic && lnext(node->args, arg) == NULL)
3725 4 : appendStringInfoString(buf, "VARIADIC ");
3726 :
3727 372 : deparseExpr((Expr *) n, context);
3728 : }
3729 : }
3730 :
3731 : /* Add ORDER BY */
3732 508 : if (node->aggorder != NIL)
3733 : {
3734 44 : appendStringInfoString(buf, " ORDER BY ");
3735 44 : appendAggOrderBy(node->aggorder, node->args, context);
3736 : }
3737 : }
3738 :
3739 : /* Add FILTER (WHERE ..) */
3740 524 : if (node->aggfilter != NULL)
3741 : {
3742 24 : appendStringInfoString(buf, ") FILTER (WHERE ");
3743 24 : deparseExpr((Expr *) node->aggfilter, context);
3744 : }
3745 :
3746 524 : appendStringInfoChar(buf, ')');
3747 524 : }
3748 :
3749 : /*
3750 : * Append ORDER BY within aggregate function.
3751 : */
3752 : static void
3753 60 : appendAggOrderBy(List *orderList, List *targetList, deparse_expr_cxt *context)
3754 : {
3755 60 : StringInfo buf = context->buf;
3756 : ListCell *lc;
3757 60 : bool first = true;
3758 :
3759 124 : foreach(lc, orderList)
3760 : {
3761 64 : SortGroupClause *srt = (SortGroupClause *) lfirst(lc);
3762 : Node *sortexpr;
3763 :
3764 64 : if (!first)
3765 4 : appendStringInfoString(buf, ", ");
3766 64 : first = false;
3767 :
3768 : /* Deparse the sort expression proper. */
3769 64 : sortexpr = deparseSortGroupClause(srt->tleSortGroupRef, targetList,
3770 : false, context);
3771 : /* Add decoration as needed. */
3772 64 : appendOrderBySuffix(srt->sortop, exprType(sortexpr), srt->nulls_first,
3773 : context);
3774 : }
3775 60 : }
3776 :
3777 : /*
3778 : * Append the ASC, DESC, USING <OPERATOR> and NULLS FIRST / NULLS LAST parts
3779 : * of an ORDER BY clause.
3780 : */
3781 : static void
3782 1792 : appendOrderBySuffix(Oid sortop, Oid sortcoltype, bool nulls_first,
3783 : deparse_expr_cxt *context)
3784 : {
3785 1792 : StringInfo buf = context->buf;
3786 : TypeCacheEntry *typentry;
3787 :
3788 : /* See whether operator is default < or > for sort expr's datatype. */
3789 1792 : typentry = lookup_type_cache(sortcoltype,
3790 : TYPECACHE_LT_OPR | TYPECACHE_GT_OPR);
3791 :
3792 1792 : if (sortop == typentry->lt_opr)
3793 1746 : appendStringInfoString(buf, " ASC");
3794 46 : else if (sortop == typentry->gt_opr)
3795 30 : appendStringInfoString(buf, " DESC");
3796 : else
3797 : {
3798 : HeapTuple opertup;
3799 : Form_pg_operator operform;
3800 :
3801 16 : appendStringInfoString(buf, " USING ");
3802 :
3803 : /* Append operator name. */
3804 16 : opertup = SearchSysCache1(OPEROID, ObjectIdGetDatum(sortop));
3805 16 : if (!HeapTupleIsValid(opertup))
3806 0 : elog(ERROR, "cache lookup failed for operator %u", sortop);
3807 16 : operform = (Form_pg_operator) GETSTRUCT(opertup);
3808 16 : deparseOperatorName(buf, operform);
3809 16 : ReleaseSysCache(opertup);
3810 : }
3811 :
3812 1792 : if (nulls_first)
3813 22 : appendStringInfoString(buf, " NULLS FIRST");
3814 : else
3815 1770 : appendStringInfoString(buf, " NULLS LAST");
3816 1792 : }
3817 :
3818 : /*
3819 : * Print the representation of a parameter to be sent to the remote side.
3820 : *
3821 : * Note: we always label the Param's type explicitly rather than relying on
3822 : * transmitting a numeric type OID in PQsendQueryParams(). This allows us to
3823 : * avoid assuming that types have the same OIDs on the remote side as they
3824 : * do locally --- they need only have the same names.
3825 : */
3826 : static void
3827 58 : printRemoteParam(int paramindex, Oid paramtype, int32 paramtypmod,
3828 : deparse_expr_cxt *context)
3829 : {
3830 58 : StringInfo buf = context->buf;
3831 58 : char *ptypename = deparse_type_name(paramtype, paramtypmod);
3832 :
3833 58 : appendStringInfo(buf, "$%d::%s", paramindex, ptypename);
3834 58 : }
3835 :
3836 : /*
3837 : * Print the representation of a placeholder for a parameter that will be
3838 : * sent to the remote side at execution time.
3839 : *
3840 : * This is used when we're just trying to EXPLAIN the remote query.
3841 : * We don't have the actual value of the runtime parameter yet, and we don't
3842 : * want the remote planner to generate a plan that depends on such a value
3843 : * anyway. Thus, we can't do something simple like "$1::paramtype".
3844 : * Instead, we emit "((SELECT null::paramtype)::paramtype)".
3845 : * In all extant versions of Postgres, the planner will see that as an unknown
3846 : * constant value, which is what we want. This might need adjustment if we
3847 : * ever make the planner flatten scalar subqueries. Note: the reason for the
3848 : * apparently useless outer cast is to ensure that the representation as a
3849 : * whole will be parsed as an a_expr and not a select_with_parens; the latter
3850 : * would do the wrong thing in the context "x = ANY(...)".
3851 : */
3852 : static void
3853 428 : printRemotePlaceholder(Oid paramtype, int32 paramtypmod,
3854 : deparse_expr_cxt *context)
3855 : {
3856 428 : StringInfo buf = context->buf;
3857 428 : char *ptypename = deparse_type_name(paramtype, paramtypmod);
3858 :
3859 428 : appendStringInfo(buf, "((SELECT null::%s)::%s)", ptypename, ptypename);
3860 428 : }
3861 :
3862 : /*
3863 : * Deparse GROUP BY clause.
3864 : */
3865 : static void
3866 330 : appendGroupByClause(List *tlist, deparse_expr_cxt *context)
3867 : {
3868 330 : StringInfo buf = context->buf;
3869 330 : Query *query = context->root->parse;
3870 : ListCell *lc;
3871 330 : bool first = true;
3872 :
3873 : /* Nothing to be done, if there's no GROUP BY clause in the query. */
3874 330 : if (!query->groupClause)
3875 128 : return;
3876 :
3877 202 : appendStringInfoString(buf, " GROUP BY ");
3878 :
3879 : /*
3880 : * Queries with grouping sets are not pushed down, so we don't expect
3881 : * grouping sets here.
3882 : */
3883 : Assert(!query->groupingSets);
3884 :
3885 : /*
3886 : * We intentionally print query->groupClause not processed_groupClause,
3887 : * leaving it to the remote planner to get rid of any redundant GROUP BY
3888 : * items again. This is necessary in case processed_groupClause reduced
3889 : * to empty, and in any case the redundancy situation on the remote might
3890 : * be different than what we think here.
3891 : */
3892 428 : foreach(lc, query->groupClause)
3893 : {
3894 226 : SortGroupClause *grp = (SortGroupClause *) lfirst(lc);
3895 :
3896 226 : if (!first)
3897 24 : appendStringInfoString(buf, ", ");
3898 226 : first = false;
3899 :
3900 226 : deparseSortGroupClause(grp->tleSortGroupRef, tlist, true, context);
3901 : }
3902 : }
3903 :
3904 : /*
3905 : * Deparse ORDER BY clause defined by the given pathkeys.
3906 : *
3907 : * The clause should use Vars from context->scanrel if !has_final_sort,
3908 : * or from context->foreignrel's targetlist if has_final_sort.
3909 : *
3910 : * We find a suitable pathkey expression (some earlier step
3911 : * should have verified that there is one) and deparse it.
3912 : */
3913 : static void
3914 1474 : appendOrderByClause(List *pathkeys, bool has_final_sort,
3915 : deparse_expr_cxt *context)
3916 : {
3917 : ListCell *lcell;
3918 : int nestlevel;
3919 1474 : StringInfo buf = context->buf;
3920 1474 : bool gotone = false;
3921 :
3922 : /* Make sure any constants in the exprs are printed portably */
3923 1474 : nestlevel = set_transmission_modes();
3924 :
3925 3214 : foreach(lcell, pathkeys)
3926 : {
3927 1740 : PathKey *pathkey = lfirst(lcell);
3928 : EquivalenceMember *em;
3929 : Expr *em_expr;
3930 : Oid oprid;
3931 :
3932 1740 : if (has_final_sort)
3933 : {
3934 : /*
3935 : * By construction, context->foreignrel is the input relation to
3936 : * the final sort.
3937 : */
3938 414 : em = find_em_for_rel_target(context->root,
3939 : pathkey->pk_eclass,
3940 : context->foreignrel);
3941 : }
3942 : else
3943 1326 : em = find_em_for_rel(context->root,
3944 : pathkey->pk_eclass,
3945 : context->scanrel);
3946 :
3947 : /*
3948 : * We don't expect any error here; it would mean that shippability
3949 : * wasn't verified earlier. For the same reason, we don't recheck
3950 : * shippability of the sort operator.
3951 : */
3952 1740 : if (em == NULL)
3953 0 : elog(ERROR, "could not find pathkey item to sort");
3954 :
3955 1740 : em_expr = em->em_expr;
3956 :
3957 : /*
3958 : * If the member is a Const expression then we needn't add it to the
3959 : * ORDER BY clause. This can happen in UNION ALL queries where the
3960 : * union child targetlist has a Const. Adding these would be
3961 : * wasteful, but also, for INT columns, an integer literal would be
3962 : * seen as an ordinal column position rather than a value to sort by.
3963 : * deparseConst() does have code to handle this, but it seems less
3964 : * effort on all accounts just to skip these for ORDER BY clauses.
3965 : */
3966 1740 : if (IsA(em_expr, Const))
3967 12 : continue;
3968 :
3969 1728 : if (!gotone)
3970 : {
3971 1468 : appendStringInfoString(buf, " ORDER BY ");
3972 1468 : gotone = true;
3973 : }
3974 : else
3975 260 : appendStringInfoString(buf, ", ");
3976 :
3977 : /*
3978 : * Lookup the operator corresponding to the compare type in the
3979 : * opclass. The datatype used by the opfamily is not necessarily the
3980 : * same as the expression type (for array types for example).
3981 : */
3982 1728 : oprid = get_opfamily_member_for_cmptype(pathkey->pk_opfamily,
3983 : em->em_datatype,
3984 : em->em_datatype,
3985 : pathkey->pk_cmptype);
3986 1728 : if (!OidIsValid(oprid))
3987 0 : elog(ERROR, "missing operator %d(%u,%u) in opfamily %u",
3988 : pathkey->pk_cmptype, em->em_datatype, em->em_datatype,
3989 : pathkey->pk_opfamily);
3990 :
3991 1728 : deparseExpr(em_expr, context);
3992 :
3993 : /*
3994 : * Here we need to use the expression's actual type to discover
3995 : * whether the desired operator will be the default or not.
3996 : */
3997 1728 : appendOrderBySuffix(oprid, exprType((Node *) em_expr),
3998 1728 : pathkey->pk_nulls_first, context);
3999 :
4000 : }
4001 1474 : reset_transmission_modes(nestlevel);
4002 1474 : }
4003 :
4004 : /*
4005 : * Deparse LIMIT/OFFSET clause.
4006 : */
4007 : static void
4008 292 : appendLimitClause(deparse_expr_cxt *context)
4009 : {
4010 292 : PlannerInfo *root = context->root;
4011 292 : StringInfo buf = context->buf;
4012 : int nestlevel;
4013 :
4014 : /* Make sure any constants in the exprs are printed portably */
4015 292 : nestlevel = set_transmission_modes();
4016 :
4017 292 : if (root->parse->limitCount)
4018 : {
4019 292 : appendStringInfoString(buf, " LIMIT ");
4020 292 : deparseExpr((Expr *) root->parse->limitCount, context);
4021 : }
4022 292 : if (root->parse->limitOffset)
4023 : {
4024 150 : appendStringInfoString(buf, " OFFSET ");
4025 150 : deparseExpr((Expr *) root->parse->limitOffset, context);
4026 : }
4027 :
4028 292 : reset_transmission_modes(nestlevel);
4029 292 : }
4030 :
4031 : /*
4032 : * appendFunctionName
4033 : * Deparses function name from given function oid.
4034 : */
4035 : static void
4036 598 : appendFunctionName(Oid funcid, deparse_expr_cxt *context)
4037 : {
4038 598 : StringInfo buf = context->buf;
4039 : HeapTuple proctup;
4040 : Form_pg_proc procform;
4041 : const char *proname;
4042 :
4043 598 : proctup = SearchSysCache1(PROCOID, ObjectIdGetDatum(funcid));
4044 598 : if (!HeapTupleIsValid(proctup))
4045 0 : elog(ERROR, "cache lookup failed for function %u", funcid);
4046 598 : procform = (Form_pg_proc) GETSTRUCT(proctup);
4047 :
4048 : /* Print schema name only if it's not pg_catalog */
4049 598 : if (procform->pronamespace != PG_CATALOG_NAMESPACE)
4050 : {
4051 : const char *schemaname;
4052 :
4053 12 : schemaname = get_namespace_name(procform->pronamespace);
4054 12 : appendStringInfo(buf, "%s.", quote_identifier(schemaname));
4055 : }
4056 :
4057 : /* Always print the function name */
4058 598 : proname = NameStr(procform->proname);
4059 598 : appendStringInfoString(buf, quote_identifier(proname));
4060 :
4061 598 : ReleaseSysCache(proctup);
4062 598 : }
4063 :
4064 : /*
4065 : * Appends a sort or group clause.
4066 : *
4067 : * Like get_rule_sortgroupclause(), returns the expression tree, so caller
4068 : * need not find it again.
4069 : */
4070 : static Node *
4071 290 : deparseSortGroupClause(Index ref, List *tlist, bool force_colno,
4072 : deparse_expr_cxt *context)
4073 : {
4074 290 : StringInfo buf = context->buf;
4075 : TargetEntry *tle;
4076 : Expr *expr;
4077 :
4078 290 : tle = get_sortgroupref_tle(ref, tlist);
4079 290 : expr = tle->expr;
4080 :
4081 290 : if (force_colno)
4082 : {
4083 : /* Use column-number form when requested by caller. */
4084 : Assert(!tle->resjunk);
4085 226 : appendStringInfo(buf, "%d", tle->resno);
4086 : }
4087 64 : else if (expr && IsA(expr, Const))
4088 : {
4089 : /*
4090 : * Force a typecast here so that we don't emit something like "GROUP
4091 : * BY 2", which will be misconstrued as a column position rather than
4092 : * a constant.
4093 : */
4094 0 : deparseConst((Const *) expr, context, 1);
4095 : }
4096 64 : else if (!expr || IsA(expr, Var))
4097 36 : deparseExpr(expr, context);
4098 : else
4099 : {
4100 : /* Always parenthesize the expression. */
4101 28 : appendStringInfoChar(buf, '(');
4102 28 : deparseExpr(expr, context);
4103 28 : appendStringInfoChar(buf, ')');
4104 : }
4105 :
4106 290 : return (Node *) expr;
4107 : }
4108 :
4109 :
4110 : /*
4111 : * Returns true if given Var is deparsed as a subquery output column, in
4112 : * which case, *relno and *colno are set to the IDs for the relation and
4113 : * column alias to the Var provided by the subquery.
4114 : */
4115 : static bool
4116 17238 : is_subquery_var(Var *node, RelOptInfo *foreignrel, int *relno, int *colno)
4117 : {
4118 17238 : PgFdwRelationInfo *fpinfo = (PgFdwRelationInfo *) foreignrel->fdw_private;
4119 17238 : RelOptInfo *outerrel = fpinfo->outerrel;
4120 17238 : RelOptInfo *innerrel = fpinfo->innerrel;
4121 :
4122 : /* Should only be called in these cases. */
4123 : Assert(IS_SIMPLE_REL(foreignrel) || IS_JOIN_REL(foreignrel));
4124 :
4125 : /*
4126 : * If the given relation isn't a join relation, it doesn't have any lower
4127 : * subqueries, so the Var isn't a subquery output column.
4128 : */
4129 17238 : if (!IS_JOIN_REL(foreignrel))
4130 4110 : return false;
4131 :
4132 : /*
4133 : * If the Var doesn't belong to any lower subqueries, it isn't a subquery
4134 : * output column.
4135 : */
4136 13128 : if (!bms_is_member(node->varno, fpinfo->lower_subquery_rels))
4137 12796 : return false;
4138 :
4139 332 : if (bms_is_member(node->varno, outerrel->relids))
4140 : {
4141 : /*
4142 : * If outer relation is deparsed as a subquery, the Var is an output
4143 : * column of the subquery; get the IDs for the relation/column alias.
4144 : */
4145 112 : if (fpinfo->make_outerrel_subquery)
4146 : {
4147 84 : get_relation_column_alias_ids(node, outerrel, relno, colno);
4148 84 : return true;
4149 : }
4150 :
4151 : /* Otherwise, recurse into the outer relation. */
4152 28 : return is_subquery_var(node, outerrel, relno, colno);
4153 : }
4154 : else
4155 : {
4156 : Assert(bms_is_member(node->varno, innerrel->relids));
4157 :
4158 : /*
4159 : * If inner relation is deparsed as a subquery, the Var is an output
4160 : * column of the subquery; get the IDs for the relation/column alias.
4161 : */
4162 220 : if (fpinfo->make_innerrel_subquery)
4163 : {
4164 220 : get_relation_column_alias_ids(node, innerrel, relno, colno);
4165 220 : return true;
4166 : }
4167 :
4168 : /* Otherwise, recurse into the inner relation. */
4169 0 : return is_subquery_var(node, innerrel, relno, colno);
4170 : }
4171 : }
4172 :
4173 : /*
4174 : * Get the IDs for the relation and column alias to given Var belonging to
4175 : * given relation, which are returned into *relno and *colno.
4176 : */
4177 : static void
4178 304 : get_relation_column_alias_ids(Var *node, RelOptInfo *foreignrel,
4179 : int *relno, int *colno)
4180 : {
4181 304 : PgFdwRelationInfo *fpinfo = (PgFdwRelationInfo *) foreignrel->fdw_private;
4182 : int i;
4183 : ListCell *lc;
4184 :
4185 : /* Get the relation alias ID */
4186 304 : *relno = fpinfo->relation_index;
4187 :
4188 : /* Get the column alias ID */
4189 304 : i = 1;
4190 376 : foreach(lc, foreignrel->reltarget->exprs)
4191 : {
4192 376 : Var *tlvar = (Var *) lfirst(lc);
4193 :
4194 : /*
4195 : * Match reltarget entries only on varno/varattno. Ideally there
4196 : * would be some cross-check on varnullingrels, but it's unclear what
4197 : * to do exactly; we don't have enough context to know what that value
4198 : * should be.
4199 : */
4200 376 : if (IsA(tlvar, Var) &&
4201 376 : tlvar->varno == node->varno &&
4202 360 : tlvar->varattno == node->varattno)
4203 : {
4204 304 : *colno = i;
4205 304 : return;
4206 : }
4207 72 : i++;
4208 : }
4209 :
4210 : /* Shouldn't get here */
4211 0 : elog(ERROR, "unexpected expression in subquery output");
4212 : }
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