diff options
Diffstat (limited to 'src/backend/optimizer/util/plancat.c')
| -rw-r--r-- | src/backend/optimizer/util/plancat.c | 42 |
1 files changed, 37 insertions, 5 deletions
diff --git a/src/backend/optimizer/util/plancat.c b/src/backend/optimizer/util/plancat.c index d29f9ff0929..5f927095edc 100644 --- a/src/backend/optimizer/util/plancat.c +++ b/src/backend/optimizer/util/plancat.c @@ -9,7 +9,7 @@ * * * IDENTIFICATION - * $PostgreSQL: pgsql/src/backend/optimizer/util/plancat.c,v 1.139 2008/01/01 19:45:50 momjian Exp $ + * $PostgreSQL: pgsql/src/backend/optimizer/util/plancat.c,v 1.140 2008/01/12 00:11:39 tgl Exp $ * *------------------------------------------------------------------------- */ @@ -47,7 +47,8 @@ get_relation_info_hook_type get_relation_info_hook = NULL; static void estimate_rel_size(Relation rel, int32 *attr_widths, BlockNumber *pages, double *tuples); -static List *get_relation_constraints(Oid relationObjectId, RelOptInfo *rel); +static List *get_relation_constraints(Oid relationObjectId, RelOptInfo *rel, + bool include_notnull); /* @@ -453,12 +454,16 @@ estimate_rel_size(Relation rel, int32 *attr_widths, * indicated by rel->relid. This allows the expressions to be easily * compared to expressions taken from WHERE. * + * If include_notnull is true, "col IS NOT NULL" expressions are generated + * and added to the result for each column that's marked attnotnull. + * * Note: at present this is invoked at most once per relation per planner * run, and in many cases it won't be invoked at all, so there seems no * point in caching the data in RelOptInfo. */ static List * -get_relation_constraints(Oid relationObjectId, RelOptInfo *rel) +get_relation_constraints(Oid relationObjectId, RelOptInfo *rel, + bool include_notnull) { List *result = NIL; Index varno = rel->relid; @@ -513,6 +518,30 @@ get_relation_constraints(Oid relationObjectId, RelOptInfo *rel) result = list_concat(result, make_ands_implicit((Expr *) cexpr)); } + + /* Add NOT NULL constraints in expression form, if requested */ + if (include_notnull && constr->has_not_null) + { + int natts = relation->rd_att->natts; + + for (i = 1; i <= natts; i++) + { + Form_pg_attribute att = relation->rd_att->attrs[i - 1]; + + if (att->attnotnull && !att->attisdropped) + { + NullTest *ntest = makeNode(NullTest); + + ntest->arg = (Expr *) makeVar(varno, + i, + att->atttypid, + att->atttypmod, + 0); + ntest->nulltesttype = IS_NOT_NULL; + result = lappend(result, ntest); + } + } + } } heap_close(relation, NoLock); @@ -567,8 +596,11 @@ relation_excluded_by_constraints(RelOptInfo *rel, RangeTblEntry *rte) if (rte->rtekind != RTE_RELATION || rte->inh) return false; - /* OK to fetch the constraint expressions */ - constraint_pred = get_relation_constraints(rte->relid, rel); + /* + * OK to fetch the constraint expressions. Include "col IS NOT NULL" + * expressions for attnotnull columns, in case we can refute those. + */ + constraint_pred = get_relation_constraints(rte->relid, rel, true); /* * We do not currently enforce that CHECK constraints contain only |