* Portions Copyright (c) 1994-5, Regents of the University of California
*
* IDENTIFICATION
- * $PostgreSQL: pgsql/src/backend/commands/explain.c,v 1.163 2007/05/04 21:29:52 tgl Exp $
+ * $PostgreSQL: pgsql/src/backend/commands/explain.c,v 1.164 2007/05/25 17:54:24 tgl Exp $
*
*-------------------------------------------------------------------------
*/
#include "utils/tuplesort.h"
+/* Hook for plugins to get control in ExplainOneQuery() */
+ExplainOneQuery_hook_type ExplainOneQuery_hook = NULL;
+/* Hook for plugins to get control in explain_get_index_name() */
+explain_get_index_name_hook_type explain_get_index_name_hook = NULL;
+
+
typedef struct ExplainState
{
/* options */
StringInfo str, int indent, ExplainState *es);
static void show_sort_info(SortState *sortstate,
StringInfo str, int indent, ExplainState *es);
+static const char *explain_get_index_name(Oid indexId);
+
/*
* ExplainQuery -
ExplainOneQuery(Query *query, ExplainStmt *stmt, const char *queryString,
ParamListInfo params, TupOutputState *tstate)
{
- PlannedStmt *plan;
- QueryDesc *queryDesc;
-
/* planner will not cope with utility statements */
if (query->commandType == CMD_UTILITY)
{
return;
}
- /* plan the query */
- plan = planner(query, 0, params);
-
- /*
- * Update snapshot command ID to ensure this query sees results of any
- * previously executed queries. (It's a bit cheesy to modify
- * ActiveSnapshot without making a copy, but for the limited ways in which
- * EXPLAIN can be invoked, I think it's OK, because the active snapshot
- * shouldn't be shared with anything else anyway.)
- */
- ActiveSnapshot->curcid = GetCurrentCommandId();
+ /* if an advisor plugin is present, let it manage things */
+ if (ExplainOneQuery_hook)
+ (*ExplainOneQuery_hook) (query, stmt, queryString, params, tstate);
+ else
+ {
+ PlannedStmt *plan;
- /* Create a QueryDesc requesting no output */
- queryDesc = CreateQueryDesc(plan,
- ActiveSnapshot, InvalidSnapshot,
- None_Receiver, params,
- stmt->analyze);
+ /* plan the query */
+ plan = planner(query, 0, params);
- ExplainOnePlan(queryDesc, stmt, tstate);
+ /* run it (if needed) and produce output */
+ ExplainOnePlan(plan, params, stmt, tstate);
+ }
}
/*
* not running the query. No cursor will be created, however.
*
* This is exported because it's called back from prepare.c in the
- * EXPLAIN EXECUTE case
- *
- * Note: the passed-in QueryDesc is freed when we're done with it
+ * EXPLAIN EXECUTE case, and because an index advisor plugin would need
+ * to call it.
*/
void
-ExplainOnePlan(QueryDesc *queryDesc, ExplainStmt *stmt,
- TupOutputState *tstate)
+ExplainOnePlan(PlannedStmt *plannedstmt, ParamListInfo params,
+ ExplainStmt *stmt, TupOutputState *tstate)
{
+ QueryDesc *queryDesc;
instr_time starttime;
double totaltime = 0;
ExplainState *es;
StringInfoData buf;
int eflags;
+ /*
+ * Update snapshot command ID to ensure this query sees results of any
+ * previously executed queries. (It's a bit cheesy to modify
+ * ActiveSnapshot without making a copy, but for the limited ways in which
+ * EXPLAIN can be invoked, I think it's OK, because the active snapshot
+ * shouldn't be shared with anything else anyway.)
+ */
+ ActiveSnapshot->curcid = GetCurrentCommandId();
+
+ /* Create a QueryDesc requesting no output */
+ queryDesc = CreateQueryDesc(plannedstmt,
+ ActiveSnapshot, InvalidSnapshot,
+ None_Receiver, params,
+ stmt->analyze);
+
INSTR_TIME_SET_CURRENT(starttime);
/* If analyzing, we need to cope with queued triggers */
if (ScanDirectionIsBackward(((IndexScan *) plan)->indexorderdir))
appendStringInfoString(str, " Backward");
appendStringInfo(str, " using %s",
- quote_identifier(get_rel_name(((IndexScan *) plan)->indexid)));
+ explain_get_index_name(((IndexScan *) plan)->indexid));
/* FALL THRU */
case T_SeqScan:
case T_BitmapHeapScan:
break;
case T_BitmapIndexScan:
appendStringInfo(str, " on %s",
- quote_identifier(get_rel_name(((BitmapIndexScan *) plan)->indexid)));
+ explain_get_index_name(((BitmapIndexScan *) plan)->indexid));
break;
case T_SubqueryScan:
if (((Scan *) plan)->scanrelid > 0)
pfree(sortinfo);
}
}
+
+/*
+ * Fetch the name of an index in an EXPLAIN
+ *
+ * We allow plugins to get control here so that plans involving hypothetical
+ * indexes can be explained.
+ */
+static const char *
+explain_get_index_name(Oid indexId)
+{
+ const char *result;
+
+ if (explain_get_index_name_hook)
+ result = (*explain_get_index_name_hook) (indexId);
+ else
+ result = NULL;
+ if (result == NULL)
+ {
+ /* default behavior: look in the catalogs and quote it */
+ result = get_rel_name(indexId);
+ if (result == NULL)
+ elog(ERROR, "cache lookup failed for index %u", indexId);
+ result = quote_identifier(result);
+ }
+ return result;
+}
* Copyright (c) 2002-2007, PostgreSQL Global Development Group
*
* IDENTIFICATION
- * $PostgreSQL: pgsql/src/backend/commands/prepare.c,v 1.75 2007/04/27 22:05:47 tgl Exp $
+ * $PostgreSQL: pgsql/src/backend/commands/prepare.c,v 1.76 2007/05/25 17:54:25 tgl Exp $
*
*-------------------------------------------------------------------------
*/
if (IsA(pstmt, PlannedStmt))
{
- QueryDesc *qdesc;
-
if (execstmt->into)
{
if (pstmt->commandType != CMD_SELECT ||
pstmt->intoClause = execstmt->into;
}
- /*
- * Update snapshot command ID to ensure this query sees results of
- * any previously executed queries. (It's a bit cheesy to modify
- * ActiveSnapshot without making a copy, but for the limited ways
- * in which EXPLAIN can be invoked, I think it's OK, because the
- * active snapshot shouldn't be shared with anything else anyway.)
- */
- ActiveSnapshot->curcid = GetCurrentCommandId();
-
- /* Create a QueryDesc requesting no output */
- qdesc = CreateQueryDesc(pstmt,
- ActiveSnapshot, InvalidSnapshot,
- None_Receiver,
- paramLI, stmt->analyze);
-
- ExplainOnePlan(qdesc, stmt, tstate);
+ ExplainOnePlan(pstmt, paramLI, stmt, tstate);
}
else
{
*
*
* IDENTIFICATION
- * $PostgreSQL: pgsql/src/backend/executor/nodeBitmapIndexscan.c,v 1.22 2007/01/05 22:19:28 momjian Exp $
+ * $PostgreSQL: pgsql/src/backend/executor/nodeBitmapIndexscan.c,v 1.23 2007/05/25 17:54:25 tgl Exp $
*
*-------------------------------------------------------------------------
*/
#endif
/*
- * close the index relation
+ * close the index relation (no-op if we didn't open it)
*/
- index_endscan(indexScanDesc);
- index_close(indexRelationDesc, NoLock);
+ if (indexScanDesc)
+ index_endscan(indexScanDesc);
+ if (indexRelationDesc)
+ index_close(indexRelationDesc, NoLock);
}
/* ----------------------------------------------------------------
indexstate->ss.ss_currentRelation = NULL;
indexstate->ss.ss_currentScanDesc = NULL;
+ /*
+ * If we are just doing EXPLAIN (ie, aren't going to run the plan),
+ * stop here. This allows an index-advisor plugin to EXPLAIN a plan
+ * containing references to nonexistent indexes.
+ */
+ if (eflags & EXEC_FLAG_EXPLAIN_ONLY)
+ return indexstate;
+
/*
* Open the index relation.
*
*
*
* IDENTIFICATION
- * $PostgreSQL: pgsql/src/backend/executor/nodeIndexscan.c,v 1.121 2007/04/06 22:33:42 tgl Exp $
+ * $PostgreSQL: pgsql/src/backend/executor/nodeIndexscan.c,v 1.122 2007/05/25 17:54:25 tgl Exp $
*
*-------------------------------------------------------------------------
*/
ExecClearTuple(node->ss.ss_ScanTupleSlot);
/*
- * close the index relation
+ * close the index relation (no-op if we didn't open it)
*/
- index_endscan(indexScanDesc);
- index_close(indexRelationDesc, NoLock);
+ if (indexScanDesc)
+ index_endscan(indexScanDesc);
+ if (indexRelationDesc)
+ index_close(indexRelationDesc, NoLock);
/*
* close the heap relation.
*/
ExecAssignScanType(&indexstate->ss, RelationGetDescr(currentRelation));
+ /*
+ * If we are just doing EXPLAIN (ie, aren't going to run the plan),
+ * stop here. This allows an index-advisor plugin to EXPLAIN a plan
+ * containing references to nonexistent indexes.
+ */
+ if (eflags & EXEC_FLAG_EXPLAIN_ONLY)
+ return indexstate;
+
/*
* Open the index relation.
*
*
*
* IDENTIFICATION
- * $PostgreSQL: pgsql/src/backend/optimizer/plan/planner.c,v 1.219 2007/05/04 01:13:44 tgl Exp $
+ * $PostgreSQL: pgsql/src/backend/optimizer/plan/planner.c,v 1.220 2007/05/25 17:54:25 tgl Exp $
*
*-------------------------------------------------------------------------
*/
#include "utils/syscache.h"
+/* Hook for plugins to get control in planner() */
+planner_hook_type planner_hook = NULL;
+
+
/* Expression kind codes for preprocess_expression */
#define EXPRKIND_QUAL 0
#define EXPRKIND_TARGET 1
*
* Query optimizer entry point
*
+ * To support loadable plugins that monitor or modify planner behavior,
+ * we provide a hook variable that lets a plugin get control before and
+ * after the standard planning process. The plugin would normally call
+ * standard_planner().
+ *
+ * Note to plugin authors: standard_planner() scribbles on its Query input,
+ * so you'd better copy that data structure if you want to plan more than once.
+ *
*****************************************************************************/
PlannedStmt *
planner(Query *parse, int cursorOptions, ParamListInfo boundParams)
+{
+ PlannedStmt *result;
+
+ if (planner_hook)
+ result = (*planner_hook) (parse, cursorOptions, boundParams);
+ else
+ result = standard_planner(parse, cursorOptions, boundParams);
+ return result;
+}
+
+PlannedStmt *
+standard_planner(Query *parse, int cursorOptions, ParamListInfo boundParams)
{
PlannedStmt *result;
PlannerGlobal *glob;
*
*
* IDENTIFICATION
- * $PostgreSQL: pgsql/src/backend/optimizer/util/plancat.c,v 1.134 2007/04/21 21:01:45 tgl Exp $
+ * $PostgreSQL: pgsql/src/backend/optimizer/util/plancat.c,v 1.135 2007/05/25 17:54:25 tgl Exp $
*
*-------------------------------------------------------------------------
*/
/* GUC parameter */
bool constraint_exclusion = false;
+/* Hook for plugins to get control in get_relation_info() */
+get_relation_info_hook_type get_relation_info_hook = NULL;
+
static void estimate_rel_size(Relation rel, int32 *attr_widths,
BlockNumber *pages, double *tuples);
rel->indexlist = indexinfos;
heap_close(relation, NoLock);
+
+ /*
+ * Allow a plugin to editorialize on the info we obtained from the
+ * catalogs. Actions might include altering the assumed relation size,
+ * removing an index, or adding a hypothetical index to the indexlist.
+ */
+ if (get_relation_info_hook)
+ (*get_relation_info_hook) (root, relationObjectId, inhparent, rel);
}
/*
* Portions Copyright (c) 1996-2007, PostgreSQL Global Development Group
* Portions Copyright (c) 1994-5, Regents of the University of California
*
- * $PostgreSQL: pgsql/src/include/commands/explain.h,v 1.30 2007/03/13 00:33:43 tgl Exp $
+ * $PostgreSQL: pgsql/src/include/commands/explain.h,v 1.31 2007/05/25 17:54:25 tgl Exp $
*
*-------------------------------------------------------------------------
*/
#include "executor/executor.h"
+/* Hook for plugins to get control in ExplainOneQuery() */
+typedef void (*ExplainOneQuery_hook_type) (Query *query,
+ ExplainStmt *stmt,
+ const char *queryString,
+ ParamListInfo params,
+ TupOutputState *tstate);
+extern DLLIMPORT ExplainOneQuery_hook_type ExplainOneQuery_hook;
+
+/* Hook for plugins to get control in explain_get_index_name() */
+typedef const char * (*explain_get_index_name_hook_type) (Oid indexId);
+extern DLLIMPORT explain_get_index_name_hook_type explain_get_index_name_hook;
+
extern void ExplainQuery(ExplainStmt *stmt, const char *queryString,
ParamListInfo params, DestReceiver *dest);
ParamListInfo params,
TupOutputState *tstate);
-extern void ExplainOnePlan(QueryDesc *queryDesc, ExplainStmt *stmt,
- TupOutputState *tstate);
+extern void ExplainOnePlan(PlannedStmt *plannedstmt, ParamListInfo params,
+ ExplainStmt *stmt, TupOutputState *tstate);
#endif /* EXPLAIN_H */
* Portions Copyright (c) 1996-2007, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
- * $PostgreSQL: pgsql/src/include/optimizer/plancat.h,v 1.43 2007/01/05 22:19:56 momjian Exp $
+ * $PostgreSQL: pgsql/src/include/optimizer/plancat.h,v 1.44 2007/05/25 17:54:25 tgl Exp $
*
*-------------------------------------------------------------------------
*/
#include "nodes/relation.h"
+/* Hook for plugins to get control in get_relation_info() */
+typedef void (*get_relation_info_hook_type) (PlannerInfo *root,
+ Oid relationObjectId,
+ bool inhparent,
+ RelOptInfo *rel);
+extern DLLIMPORT get_relation_info_hook_type get_relation_info_hook;
+
extern void get_relation_info(PlannerInfo *root, Oid relationObjectId,
bool inhparent, RelOptInfo *rel);
* Portions Copyright (c) 1996-2007, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
- * $PostgreSQL: pgsql/src/include/optimizer/planner.h,v 1.39 2007/04/16 01:14:58 tgl Exp $
+ * $PostgreSQL: pgsql/src/include/optimizer/planner.h,v 1.40 2007/05/25 17:54:25 tgl Exp $
*
*-------------------------------------------------------------------------
*/
#include "nodes/relation.h"
+/* Hook for plugins to get control in planner() */
+typedef PlannedStmt * (*planner_hook_type) (Query *parse,
+ int cursorOptions,
+ ParamListInfo boundParams);
+extern DLLIMPORT planner_hook_type planner_hook;
+
+
extern PlannedStmt *planner(Query *parse, int cursorOptions,
ParamListInfo boundParams);
+extern PlannedStmt *standard_planner(Query *parse, int cursorOptions,
+ ParamListInfo boundParams);
extern Plan *subquery_planner(PlannerGlobal *glob, Query *parse,
Index level, double tuple_fraction,
PlannerInfo **subroot);
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