diff options
| -rw-r--r-- | src/backend/partitioning/partprune.c | 56 | ||||
| -rw-r--r-- | src/test/regress/expected/partition_prune.out | 18 | ||||
| -rw-r--r-- | src/test/regress/sql/partition_prune.sql | 4 |
3 files changed, 52 insertions, 26 deletions
diff --git a/src/backend/partitioning/partprune.c b/src/backend/partitioning/partprune.c index 09c4ed83b68..2ed1e44c181 100644 --- a/src/backend/partitioning/partprune.c +++ b/src/backend/partitioning/partprune.c @@ -849,10 +849,11 @@ get_matching_partitions(PartitionPruneContext *context, List *pruning_steps) * the context's steps list. Each step is assigned a step identifier, unique * even across recursive calls. * - * If we find clauses that are mutually contradictory, or a pseudoconstant - * clause that contains false, we set context->contradictory to true and - * return NIL (that is, no pruning steps). Caller should consider all - * partitions as pruned in that case. + * If we find clauses that are mutually contradictory, or contradictory with + * the partitioning constraint, or a pseudoconstant clause that contains + * false, we set context->contradictory to true and return NIL (that is, no + * pruning steps). Caller should consider all partitions as pruned in that + * case. */ static List * gen_partprune_steps_internal(GeneratePruningStepsContext *context, @@ -942,35 +943,15 @@ gen_partprune_steps_internal(GeneratePruningStepsContext *context, } else { + PartitionPruneStep *orstep; + /* * The arg didn't contain a clause matching this * partition key. We cannot prune using such an arg. * To indicate that to the pruning code, we must * construct a dummy PartitionPruneStepCombine whose * source_stepids is set to an empty List. - * - * However, if we can prove using constraint exclusion - * that the clause refutes the table's partition - * constraint (if it's sub-partitioned), we need not - * bother with that. That is, we effectively ignore - * this OR arm. */ - List *partconstr = context->rel->partition_qual; - PartitionPruneStep *orstep; - - if (partconstr) - { - partconstr = (List *) - expression_planner((Expr *) partconstr); - if (context->rel->relid != 1) - ChangeVarNodes((Node *) partconstr, 1, - context->rel->relid, 0); - if (predicate_refuted_by(partconstr, - list_make1(arg), - false)) - continue; - } - orstep = gen_prune_step_combine(context, NIL, PARTPRUNE_COMBINE_UNION); arg_stepids = lappend_int(arg_stepids, orstep->step_id); @@ -1039,6 +1020,29 @@ gen_partprune_steps_internal(GeneratePruningStepsContext *context, } /* + * If the clause contradicts the partition constraint, mark the clause + * as contradictory and we're done. This is particularly helpful to + * prune the default partition. + */ + if (context->rel->partition_qual) + { + List *partconstr; + + partconstr = (List *) + expression_planner((Expr *) context->rel->partition_qual); + if (context->rel->relid != 1) + ChangeVarNodes((Node *) partconstr, 1, + context->rel->relid, 0); + if (predicate_refuted_by(partconstr, + list_make1(clause), + false)) + { + context->contradictory = true; + return NIL; + } + } + + /* * See if we can match this clause to any of the partition keys. */ for (i = 0; i < part_scheme->partnatts; i++) diff --git a/src/test/regress/expected/partition_prune.out b/src/test/regress/expected/partition_prune.out index 2d3229fd73f..6ccc91d390c 100644 --- a/src/test/regress/expected/partition_prune.out +++ b/src/test/regress/expected/partition_prune.out @@ -592,6 +592,24 @@ explain (costs off) select * from rlp where a < 1 or (a > 20 and a < 25); Filter: ((a < 1) OR ((a > 20) AND (a < 25))) (5 rows) +-- where clause contradicts sub-partition's constraint +explain (costs off) select * from rlp where a = 20 or a = 40; + QUERY PLAN +---------------------------------------- + Append + -> Seq Scan on rlp4_1 + Filter: ((a = 20) OR (a = 40)) + -> Seq Scan on rlp5_default + Filter: ((a = 20) OR (a = 40)) +(5 rows) + +explain (costs off) select * from rlp3 where a = 20; /* empty */ + QUERY PLAN +-------------------------- + Result + One-Time Filter: false +(2 rows) + -- redundant clauses are eliminated explain (costs off) select * from rlp where a > 1 and a = 10; /* only default */ QUERY PLAN diff --git a/src/test/regress/sql/partition_prune.sql b/src/test/regress/sql/partition_prune.sql index efdedaaeb8f..a26c2f0e72b 100644 --- a/src/test/regress/sql/partition_prune.sql +++ b/src/test/regress/sql/partition_prune.sql @@ -85,6 +85,10 @@ explain (costs off) select * from rlp where a = 29; explain (costs off) select * from rlp where a >= 29; explain (costs off) select * from rlp where a < 1 or (a > 20 and a < 25); +-- where clause contradicts sub-partition's constraint +explain (costs off) select * from rlp where a = 20 or a = 40; +explain (costs off) select * from rlp3 where a = 20; /* empty */ + -- redundant clauses are eliminated explain (costs off) select * from rlp where a > 1 and a = 10; /* only default */ explain (costs off) select * from rlp where a > 1 and a >=15; /* rlp3 onwards, including default */ |