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Diffstat (limited to 'src/backend/partitioning/partdesc.c')
| -rw-r--r-- | src/backend/partitioning/partdesc.c | 221 |
1 files changed, 221 insertions, 0 deletions
diff --git a/src/backend/partitioning/partdesc.c b/src/backend/partitioning/partdesc.c new file mode 100644 index 00000000000..8a4b63aa268 --- /dev/null +++ b/src/backend/partitioning/partdesc.c @@ -0,0 +1,221 @@ +/*------------------------------------------------------------------------- + * + * partdesc.c + * Support routines for manipulating partition descriptors + * + * Portions Copyright (c) 1996-2018, PostgreSQL Global Development Group + * Portions Copyright (c) 1994, Regents of the University of California + * + * IDENTIFICATION + * src/backend/partitioning/partdesc.c + * + *------------------------------------------------------------------------- + */ + +#include "postgres.h" + +#include "catalog/partition.h" +#include "catalog/pg_inherits.h" +#include "partitioning/partbounds.h" +#include "partitioning/partdesc.h" +#include "utils/builtins.h" +#include "utils/lsyscache.h" +#include "utils/memutils.h" +#include "utils/rel.h" +#include "utils/partcache.h" +#include "utils/syscache.h" + +/* + * RelationBuildPartitionDesc + * Form rel's partition descriptor + * + * Not flushed from the cache by RelationClearRelation() unless changed because + * of addition or removal of partition. + */ +void +RelationBuildPartitionDesc(Relation rel) +{ + PartitionDesc partdesc; + PartitionBoundInfo boundinfo = NULL; + List *inhoids; + PartitionBoundSpec **boundspecs = NULL; + Oid *oids = NULL; + ListCell *cell; + int i, + nparts; + PartitionKey key = RelationGetPartitionKey(rel); + MemoryContext oldcxt; + int *mapping; + + /* Get partition oids from pg_inherits */ + inhoids = find_inheritance_children(RelationGetRelid(rel), NoLock); + nparts = list_length(inhoids); + + if (nparts > 0) + { + oids = palloc(nparts * sizeof(Oid)); + boundspecs = palloc(nparts * sizeof(PartitionBoundSpec *)); + } + + /* Collect bound spec nodes for each partition */ + i = 0; + foreach(cell, inhoids) + { + Oid inhrelid = lfirst_oid(cell); + HeapTuple tuple; + Datum datum; + bool isnull; + PartitionBoundSpec *boundspec; + + tuple = SearchSysCache1(RELOID, inhrelid); + if (!HeapTupleIsValid(tuple)) + elog(ERROR, "cache lookup failed for relation %u", inhrelid); + + datum = SysCacheGetAttr(RELOID, tuple, + Anum_pg_class_relpartbound, + &isnull); + if (isnull) + elog(ERROR, "null relpartbound for relation %u", inhrelid); + boundspec = stringToNode(TextDatumGetCString(datum)); + if (!IsA(boundspec, PartitionBoundSpec)) + elog(ERROR, "invalid relpartbound for relation %u", inhrelid); + + /* + * Sanity check: If the PartitionBoundSpec says this is the default + * partition, its OID should correspond to whatever's stored in + * pg_partitioned_table.partdefid; if not, the catalog is corrupt. + */ + if (boundspec->is_default) + { + Oid partdefid; + + partdefid = get_default_partition_oid(RelationGetRelid(rel)); + if (partdefid != inhrelid) + elog(ERROR, "expected partdefid %u, but got %u", + inhrelid, partdefid); + } + + oids[i] = inhrelid; + boundspecs[i] = boundspec; + ++i; + ReleaseSysCache(tuple); + } + + /* Now build the actual relcache partition descriptor */ + rel->rd_pdcxt = AllocSetContextCreate(CacheMemoryContext, + "partition descriptor", + ALLOCSET_DEFAULT_SIZES); + MemoryContextCopyAndSetIdentifier(rel->rd_pdcxt, + RelationGetRelationName(rel)); + + oldcxt = MemoryContextSwitchTo(rel->rd_pdcxt); + partdesc = (PartitionDescData *) palloc0(sizeof(PartitionDescData)); + partdesc->nparts = nparts; + /* oids and boundinfo are allocated below. */ + + MemoryContextSwitchTo(oldcxt); + + if (nparts == 0) + { + rel->rd_partdesc = partdesc; + return; + } + + /* First create PartitionBoundInfo */ + boundinfo = partition_bounds_create(boundspecs, nparts, key, &mapping); + + /* Now copy boundinfo and oids into partdesc. */ + oldcxt = MemoryContextSwitchTo(rel->rd_pdcxt); + partdesc->boundinfo = partition_bounds_copy(boundinfo, key); + partdesc->oids = (Oid *) palloc(partdesc->nparts * sizeof(Oid)); + partdesc->is_leaf = (bool *) palloc(partdesc->nparts * sizeof(bool)); + + /* + * Now assign OIDs from the original array into mapped indexes of the + * result array. The order of OIDs in the former is defined by the + * catalog scan that retrieved them, whereas that in the latter is defined + * by canonicalized representation of the partition bounds. + */ + for (i = 0; i < partdesc->nparts; i++) + { + int index = mapping[i]; + + partdesc->oids[index] = oids[i]; + /* Record if the partition is a leaf partition */ + partdesc->is_leaf[index] = + (get_rel_relkind(oids[i]) != RELKIND_PARTITIONED_TABLE); + } + MemoryContextSwitchTo(oldcxt); + + rel->rd_partdesc = partdesc; +} + +/* + * equalPartitionDescs + * Compare two partition descriptors for logical equality + */ +bool +equalPartitionDescs(PartitionKey key, PartitionDesc partdesc1, + PartitionDesc partdesc2) +{ + int i; + + if (partdesc1 != NULL) + { + if (partdesc2 == NULL) + return false; + if (partdesc1->nparts != partdesc2->nparts) + return false; + + Assert(key != NULL || partdesc1->nparts == 0); + + /* + * Same oids? If the partitioning structure did not change, that is, + * no partitions were added or removed to the relation, the oids array + * should still match element-by-element. + */ + for (i = 0; i < partdesc1->nparts; i++) + { + if (partdesc1->oids[i] != partdesc2->oids[i]) + return false; + } + + /* + * Now compare partition bound collections. The logic to iterate over + * the collections is private to partition.c. + */ + if (partdesc1->boundinfo != NULL) + { + if (partdesc2->boundinfo == NULL) + return false; + + if (!partition_bounds_equal(key->partnatts, key->parttyplen, + key->parttypbyval, + partdesc1->boundinfo, + partdesc2->boundinfo)) + return false; + } + else if (partdesc2->boundinfo != NULL) + return false; + } + else if (partdesc2 != NULL) + return false; + + return true; +} + +/* + * get_default_oid_from_partdesc + * + * Given a partition descriptor, return the OID of the default partition, if + * one exists; else, return InvalidOid. + */ +Oid +get_default_oid_from_partdesc(PartitionDesc partdesc) +{ + if (partdesc && partdesc->boundinfo && + partition_bound_has_default(partdesc->boundinfo)) + return partdesc->oids[partdesc->boundinfo->default_index]; + + return InvalidOid; +} |