diff options
| -rw-r--r-- | src/backend/pgxc/plan/planner.c | 76 |
1 files changed, 71 insertions, 5 deletions
diff --git a/src/backend/pgxc/plan/planner.c b/src/backend/pgxc/plan/planner.c index 83ee829c50..02b863a4c1 100644 --- a/src/backend/pgxc/plan/planner.c +++ b/src/backend/pgxc/plan/planner.c @@ -150,6 +150,8 @@ static bool examine_conditions_walker(Node *expr_node, XCWalkerContext *context) static int handle_limit_offset(RemoteQuery *query_step, Query *query, PlannedStmt *plan_stmt); static void InitXCWalkerContext(XCWalkerContext *context); static void validate_part_col_updatable(const Query *query); +static bool is_pgxc_safe_func(Oid funcid); + /* * Find position of specified substring in the string @@ -850,7 +852,6 @@ examine_conditions_walker(Node *expr_node, XCWalkerContext *context) return false; } } - else if (IsA(expr_node, BoolExpr)) { BoolExpr *boolexpr = (BoolExpr *) expr_node; @@ -1082,7 +1083,7 @@ examine_conditions_walker(Node *expr_node, XCWalkerContext *context) /* See if the function is immutable, otherwise give up */ if (IsA(expr_node, FuncExpr)) { - if (!is_immutable_func(((FuncExpr*) expr_node)->funcid)) + if (!is_pgxc_safe_func(((FuncExpr*) expr_node)->funcid)) return true; } @@ -1273,10 +1274,16 @@ get_plan_nodes_walker(Node *query_node, XCWalkerContext *context) */ if (query->targetList) { + ExecNodes *save_nodes = context->query_step->exec_nodes; + int save_varno = context->varno; + foreach(item, query->targetList) { TargetEntry *target = (TargetEntry *) lfirst(item); + context->query_step->exec_nodes = NULL; + context->varno = 0; + if (examine_conditions_walker((Node*)target->expr, context)) return true; @@ -1290,11 +1297,11 @@ get_plan_nodes_walker(Node *query_node, XCWalkerContext *context) return true; pfree(context->query_step->exec_nodes); - context->query_step->exec_nodes = NULL; } } + context->query_step->exec_nodes = save_nodes; + context->varno = save_varno; } - /* Look for JOIN syntax joins */ foreach(item, query->jointree->fromlist) { @@ -2554,7 +2561,7 @@ pgxc_planner(Query *query, int cursorOptions, ParamListInfo boundParams) { ereport(ERROR, (errcode(ERRCODE_STATEMENT_TOO_COMPLEX), - (errmsg("Complex and correlated UPDATE and DELETE not yet supported")))); + (errmsg("UPDATE and DELETE that are correlated or use non-immutable functions not yet supported")))); } /* @@ -2940,3 +2947,62 @@ validate_part_col_updatable(const Query *query) } } } + +/* + * See if it is safe to use this function in single step. + * + * Based on is_immutable_func from postgresql_fdw.c + * We add an exeption for base postgresql functions, to + * allow now() and others to still execute as part of single step + * queries. + * + * PGXCTODO - we currently make the false assumption that immutable + * functions will not write to the database. This could be addressed + * by either a more thorough analysis of functions at + * creation time or additional tags at creation time (preferably + * in standard PostgreSQL). Ideally such functionality could be + * committed back to standard PostgreSQL. + */ +bool +is_pgxc_safe_func(Oid funcid) +{ + HeapTuple tp; + bool isnull; + Datum datum; + bool ret_val = false; + + tp = SearchSysCache(PROCOID, ObjectIdGetDatum(funcid), 0, 0, 0); + if (!HeapTupleIsValid(tp)) + elog(ERROR, "cache lookup failed for function %u", funcid); + +#ifdef DEBUG_FDW + /* print function name and its immutability */ + { + char *proname; + datum = SysCacheGetAttr(PROCOID, tp, Anum_pg_proc_proname, &isnull); + proname = pstrdup(DatumGetName(datum)->data); + elog(DEBUG1, "func %s(%u) is%s immutable", proname, funcid, + (DatumGetChar(datum) == PROVOLATILE_IMMUTABLE) ? "" : " not"); + pfree(proname); + } +#endif + + datum = SysCacheGetAttr(PROCOID, tp, Anum_pg_proc_provolatile, &isnull); + + if (DatumGetChar(datum) == PROVOLATILE_IMMUTABLE) + ret_val = true; + /* + * Also allow stable and volatile ones that are in the PG_CATALOG_NAMESPACE + * this allows now() and others that do not update the database + * PGXCTODO - examine default functions carefully for those that may + * write to the database. + */ + else + { + datum = SysCacheGetAttr(PROCOID, tp, Anum_pg_proc_pronamespace, &isnull); + if (DatumGetObjectId(datum) == PG_CATALOG_NAMESPACE) + ret_val = true; + } + ReleaseSysCache(tp); + return ret_val; +} |