diff options
Diffstat (limited to 'src/backend/partitioning/partdesc.c')
| -rw-r--r-- | src/backend/partitioning/partdesc.c | 100 |
1 files changed, 69 insertions, 31 deletions
diff --git a/src/backend/partitioning/partdesc.c b/src/backend/partitioning/partdesc.c index 58570fecfdc..12ef36a73e6 100644 --- a/src/backend/partitioning/partdesc.c +++ b/src/backend/partitioning/partdesc.c @@ -37,7 +37,7 @@ typedef struct PartitionDirectoryData { MemoryContext pdir_mcxt; HTAB *pdir_hash; - bool include_detached; + bool omit_detached; } PartitionDirectoryData; typedef struct PartitionDirectoryEntry @@ -47,7 +47,8 @@ typedef struct PartitionDirectoryEntry PartitionDesc pd; } PartitionDirectoryEntry; -static void RelationBuildPartitionDesc(Relation rel, bool include_detached); +static PartitionDesc RelationBuildPartitionDesc(Relation rel, + bool omit_detached); /* @@ -60,18 +61,29 @@ static void RelationBuildPartitionDesc(Relation rel, bool include_detached); * for callers to continue to use that pointer as long as (a) they hold the * relation open, and (b) they hold a relation lock strong enough to ensure * that the data doesn't become stale. + * + * The above applies to partition descriptors that are complete regarding + * partitions concurrently being detached. When a descriptor that omits + * partitions being detached is requested (and such partitions are present), + * said descriptor is not part of relcache and so it isn't freed by + * invalidations either. Caller must not use such a descriptor beyond the + * current Portal. */ PartitionDesc -RelationGetPartitionDesc(Relation rel, bool include_detached) +RelationGetPartitionDesc(Relation rel, bool omit_detached) { - if (rel->rd_rel->relkind != RELKIND_PARTITIONED_TABLE) - return NULL; + Assert(rel->rd_rel->relkind == RELKIND_PARTITIONED_TABLE); - if (unlikely(rel->rd_partdesc == NULL || - rel->rd_partdesc->includes_detached != include_detached)) - RelationBuildPartitionDesc(rel, include_detached); + /* + * If relcache has a partition descriptor, use that. However, we can only + * do so when we are asked to include all partitions including detached; + * and also when we know that there are no detached partitions. + */ + if (likely(rel->rd_partdesc && + (!rel->rd_partdesc->detached_exist || !omit_detached))) + return rel->rd_partdesc; - return rel->rd_partdesc; + return RelationBuildPartitionDesc(rel, omit_detached); } /* @@ -88,9 +100,15 @@ RelationGetPartitionDesc(Relation rel, bool include_detached) * context the current context except in very brief code sections, out of fear * that some of our callees allocate memory on their own which would be leaked * permanently. + * + * As a special case, partition descriptors that are requested to omit + * partitions being detached (and which contain such partitions) are transient + * and are not associated with the relcache entry. Such descriptors only last + * through the requesting Portal, so we use the corresponding memory context + * for them. */ -static void -RelationBuildPartitionDesc(Relation rel, bool include_detached) +static PartitionDesc +RelationBuildPartitionDesc(Relation rel, bool omit_detached) { PartitionDesc partdesc; PartitionBoundInfo boundinfo = NULL; @@ -98,6 +116,7 @@ RelationBuildPartitionDesc(Relation rel, bool include_detached) PartitionBoundSpec **boundspecs = NULL; Oid *oids = NULL; bool *is_leaf = NULL; + bool detached_exist; ListCell *cell; int i, nparts; @@ -112,8 +131,8 @@ RelationBuildPartitionDesc(Relation rel, bool include_detached) * concurrently, whatever this function returns will be accurate as of * some well-defined point in time. */ - inhoids = find_inheritance_children(RelationGetRelid(rel), include_detached, - NoLock); + inhoids = find_inheritance_children(RelationGetRelid(rel), omit_detached, + NoLock, &detached_exist); nparts = list_length(inhoids); /* Allocate working arrays for OIDs, leaf flags, and boundspecs. */ @@ -234,6 +253,7 @@ RelationBuildPartitionDesc(Relation rel, bool include_detached) partdesc = (PartitionDescData *) MemoryContextAllocZero(new_pdcxt, sizeof(PartitionDescData)); partdesc->nparts = nparts; + partdesc->detached_exist = detached_exist; /* If there are no partitions, the rest of the partdesc can stay zero */ if (nparts > 0) { @@ -241,7 +261,6 @@ RelationBuildPartitionDesc(Relation rel, bool include_detached) partdesc->boundinfo = partition_bounds_copy(boundinfo, key); partdesc->oids = (Oid *) palloc(nparts * sizeof(Oid)); partdesc->is_leaf = (bool *) palloc(nparts * sizeof(bool)); - partdesc->includes_detached = include_detached; /* * Assign OIDs from the original array into mapped indexes of the @@ -261,22 +280,41 @@ RelationBuildPartitionDesc(Relation rel, bool include_detached) } /* - * We have a fully valid partdesc ready to store into the relcache. - * Reparent it so it has the right lifespan. + * We have a fully valid partdesc. Reparent it so that it has the right + * lifespan, and if appropriate put it into the relation's relcache entry. */ - MemoryContextSetParent(new_pdcxt, CacheMemoryContext); + if (omit_detached && detached_exist) + { + /* + * A transient partition descriptor is only good for the current + * statement, so make it a child of the current portal's context. + */ + MemoryContextSetParent(new_pdcxt, PortalContext); + } + else + { + /* + * This partdesc goes into relcache. + */ - /* - * But first, a kluge: if there's an old rd_pdcxt, it contains an old - * partition descriptor that may still be referenced somewhere. Preserve - * it, while not leaking it, by reattaching it as a child context of the - * new rd_pdcxt. Eventually it will get dropped by either RelationClose - * or RelationClearRelation. - */ - if (rel->rd_pdcxt != NULL) - MemoryContextSetParent(rel->rd_pdcxt, new_pdcxt); - rel->rd_pdcxt = new_pdcxt; - rel->rd_partdesc = partdesc; + MemoryContextSetParent(new_pdcxt, CacheMemoryContext); + + /* + * But first, a kluge: if there's an old rd_pdcxt, it contains an old + * partition descriptor that may still be referenced somewhere. + * Preserve it, while not leaking it, by reattaching it as a child + * context of the new rd_pdcxt. Eventually it will get dropped by + * either RelationClose or RelationClearRelation. + */ + if (rel->rd_pdcxt != NULL) + MemoryContextSetParent(rel->rd_pdcxt, new_pdcxt); + rel->rd_pdcxt = new_pdcxt; + + /* Store it into relcache */ + rel->rd_partdesc = partdesc; + } + + return partdesc; } /* @@ -284,7 +322,7 @@ RelationBuildPartitionDesc(Relation rel, bool include_detached) * Create a new partition directory object. */ PartitionDirectory -CreatePartitionDirectory(MemoryContext mcxt, bool include_detached) +CreatePartitionDirectory(MemoryContext mcxt, bool omit_detached) { MemoryContext oldcontext = MemoryContextSwitchTo(mcxt); PartitionDirectory pdir; @@ -299,7 +337,7 @@ CreatePartitionDirectory(MemoryContext mcxt, bool include_detached) pdir->pdir_hash = hash_create("partition directory", 256, &ctl, HASH_ELEM | HASH_BLOBS | HASH_CONTEXT); - pdir->include_detached = include_detached; + pdir->omit_detached = omit_detached; MemoryContextSwitchTo(oldcontext); return pdir; @@ -332,7 +370,7 @@ PartitionDirectoryLookup(PartitionDirectory pdir, Relation rel) */ RelationIncrementReferenceCount(rel); pde->rel = rel; - pde->pd = RelationGetPartitionDesc(rel, pdir->include_detached); + pde->pd = RelationGetPartitionDesc(rel, pdir->omit_detached); Assert(pde->pd != NULL); } return pde->pd; |