diff options
Diffstat (limited to 'src/backend/utils/cache/partcache.c')
| -rw-r--r-- | src/backend/utils/cache/partcache.c | 32 |
1 files changed, 26 insertions, 6 deletions
diff --git a/src/backend/utils/cache/partcache.c b/src/backend/utils/cache/partcache.c index 342ab4dbaa6..e2144c83aba 100644 --- a/src/backend/utils/cache/partcache.c +++ b/src/backend/utils/cache/partcache.c @@ -37,9 +37,32 @@ #include "utils/syscache.h" +static void RelationBuildPartitionKey(Relation relation); static List *generate_partition_qual(Relation rel); /* + * RelationGetPartitionKey -- get partition key, if relation is partitioned + * + * Note: partition keys are not allowed to change after the partitioned rel + * is created. RelationClearRelation knows this and preserves rd_partkey + * across relcache rebuilds, as long as the relation is open. Therefore, + * even though we hand back a direct pointer into the relcache entry, it's + * safe for callers to continue to use that pointer as long as they hold + * the relation open. + */ +PartitionKey +RelationGetPartitionKey(Relation rel) +{ + if (rel->rd_rel->relkind != RELKIND_PARTITIONED_TABLE) + return NULL; + + if (unlikely(rel->rd_partkey == NULL)) + RelationBuildPartitionKey(rel); + + return rel->rd_partkey; +} + +/* * RelationBuildPartitionKey * Build partition key data of relation, and attach to relcache * @@ -54,7 +77,7 @@ static List *generate_partition_qual(Relation rel); * that some of our callees allocate memory on their own which would be leaked * permanently. */ -void +static void RelationBuildPartitionKey(Relation relation) { Form_pg_partitioned_table form; @@ -74,12 +97,9 @@ RelationBuildPartitionKey(Relation relation) tuple = SearchSysCache1(PARTRELID, ObjectIdGetDatum(RelationGetRelid(relation))); - /* - * The following happens when we have created our pg_class entry but not - * the pg_partitioned_table entry yet. - */ if (!HeapTupleIsValid(tuple)) - return; + elog(ERROR, "cache lookup failed for partition key of relation %u", + RelationGetRelid(relation)); partkeycxt = AllocSetContextCreate(CurTransactionContext, "partition key", |