diff options
Diffstat (limited to 'src/backend/optimizer/path/clausesel.c')
| -rw-r--r-- | src/backend/optimizer/path/clausesel.c | 34 |
1 files changed, 31 insertions, 3 deletions
diff --git a/src/backend/optimizer/path/clausesel.c b/src/backend/optimizer/path/clausesel.c index 3ff02902f7..f595a3f07f 100644 --- a/src/backend/optimizer/path/clausesel.c +++ b/src/backend/optimizer/path/clausesel.c @@ -8,7 +8,7 @@ * * * IDENTIFICATION - * $PostgreSQL: pgsql/src/backend/optimizer/path/clausesel.c,v 1.79 2006/03/07 01:00:15 tgl Exp $ + * $PostgreSQL: pgsql/src/backend/optimizer/path/clausesel.c,v 1.80 2006/07/01 18:38:32 tgl Exp $ * *------------------------------------------------------------------------- */ @@ -117,10 +117,18 @@ clauselist_selectivity(PlannerInfo *root, /* * Check for being passed a RestrictInfo. + * + * If it's a pseudoconstant RestrictInfo, then s2 is either 1.0 or + * 0.0; just use that rather than looking for range pairs. */ if (IsA(clause, RestrictInfo)) { rinfo = (RestrictInfo *) clause; + if (rinfo->pseudoconstant) + { + s1 = s1 * s2; + continue; + } clause = (Node *) rinfo->clause; } else @@ -423,6 +431,20 @@ clause_selectivity(PlannerInfo *root, rinfo = (RestrictInfo *) clause; /* + * If the clause is marked pseudoconstant, then it will be used as + * a gating qual and should not affect selectivity estimates; hence + * return 1.0. The only exception is that a constant FALSE may + * be taken as having selectivity 0.0, since it will surely mean + * no rows out of the plan. This case is simple enough that we + * need not bother caching the result. + */ + if (rinfo->pseudoconstant) + { + if (! IsA(rinfo->clause, Const)) + return s1; + } + + /* * If possible, cache the result of the selectivity calculation for * the clause. We can cache if varRelid is zero or the clause * contains only vars of that relid --- otherwise varRelid will affect @@ -509,7 +531,10 @@ clause_selectivity(PlannerInfo *root, else if (IsA(clause, Const)) { /* bool constant is pretty easy... */ - s1 = ((bool) ((Const *) clause)->constvalue) ? 1.0 : 0.0; + Const *con = (Const *) clause; + + s1 = con->constisnull ? 0.0 : + DatumGetBool(con->constvalue) ? 1.0 : 0.0; } else if (IsA(clause, Param)) { @@ -519,7 +544,10 @@ clause_selectivity(PlannerInfo *root, if (IsA(subst, Const)) { /* bool constant is pretty easy... */ - s1 = ((bool) ((Const *) subst)->constvalue) ? 1.0 : 0.0; + Const *con = (Const *) subst; + + s1 = con->constisnull ? 0.0 : + DatumGetBool(con->constvalue) ? 1.0 : 0.0; } else { |