|
9 | 9 | * |
10 | 10 | * |
11 | 11 | * IDENTIFICATION |
12 | | - * $PostgreSQL: pgsql/src/backend/optimizer/path/indxpath.c,v 1.157 2004/03/07 05:43:53 tgl Exp $ |
| 12 | + * $PostgreSQL: pgsql/src/backend/optimizer/path/indxpath.c,v 1.158 2004/03/27 00:24:28 tgl Exp $ |
13 | 13 | * |
14 | 14 | *------------------------------------------------------------------------- |
15 | 15 | */ |
|
22 | 22 | #include"catalog/pg_namespace.h" |
23 | 23 | #include"catalog/pg_opclass.h" |
24 | 24 | #include"catalog/pg_operator.h" |
| 25 | +#include"catalog/pg_proc.h" |
25 | 26 | #include"catalog/pg_type.h" |
26 | 27 | #include"executor/executor.h" |
27 | 28 | #include"nodes/makefuncs.h" |
@@ -990,9 +991,10 @@ static const StrategyNumber |
990 | 991 | * and constants can be different but the operators must be in the same btree |
991 | 992 | * operator class. We use the above operator implication table to be able to |
992 | 993 | * derive implications between nonidentical clauses. (Note: "foo" is known |
993 | | - * immutable, and constants are surely immutable, and we assume that operators |
994 | | - * that are in btree opclasses are immutable, so there's no need to do extra |
995 | | - * mutability checks in this case either.) |
| 994 | + * immutable, and constants are surely immutable, but we have to check that |
| 995 | + * the operators are too. As of 7.5 it's possible for opclasses to contain |
| 996 | + * operators that are merely stable, and we dare not make deductions with |
| 997 | + * these.) |
996 | 998 | * |
997 | 999 | * Eventually, rtree operators could also be handled by defining an |
998 | 1000 | * appropriate "RT_implic_table" array. |
@@ -1279,8 +1281,20 @@ pred_test_simple_clause(Expr *predicate, Node *clause) |
1279 | 1281 | } |
1280 | 1282 | if (OidIsValid(test_op)) |
1281 | 1283 | { |
1282 | | -found= true; |
1283 | | -break; |
| 1284 | +/* |
| 1285 | + * Last check: test_op must be immutable. |
| 1286 | + * |
| 1287 | + * Note that we require only the test_op to be immutable, not |
| 1288 | + * the original clause_op. (pred_op must be immutable, else it |
| 1289 | + * would not be allowed in an index predicate.) Essentially |
| 1290 | + * we are assuming that the opclass is consistent even if it |
| 1291 | + * contains operators that are merely stable. |
| 1292 | + */ |
| 1293 | +if (op_volatile(test_op)==PROVOLATILE_IMMUTABLE) |
| 1294 | +{ |
| 1295 | +found= true; |
| 1296 | +break; |
| 1297 | +} |
1284 | 1298 | } |
1285 | 1299 | } |
1286 | 1300 |
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