Copy information from the relcache instead of pointing to it.

robertmhaas · robertmhaas · commit 45866c75507f · 2017-10-06T15:28:07.000-04:00
We have the relations continuously locked, but not open, so relcache pointers are not guaranteed to be stable. Per buildfarm member prion. Ashutosh Bapat. I fixed a typo. Discussion: http://postgr.es/m/CAFjFpRcRBqoKLZSNmRsjKr81uEP=ennvqSQaXVCCBTXvJ2rW+Q@mail.gmail.com
diff --git a/src/backend/catalog/partition.c b/src/backend/catalog/partition.c
@@ -701,6 +701,74 @@ partition_bounds_equal(int partnatts, int16 *parttyplen, bool *parttypbyval,
 	return true;
 }
 
+/*
+ * Return a copy of given PartitionBoundInfo structure. The data types of bounds
+ * are described by given partition key specificiation.
+ */
+extern PartitionBoundInfo
+partition_bounds_copy(PartitionBoundInfo src,
+					  PartitionKey key)
+{
+	PartitionBoundInfo	dest;
+	int		i;
+	int		ndatums;
+	int		partnatts;
+	int		num_indexes;
+
+	dest = (PartitionBoundInfo) palloc(sizeof(PartitionBoundInfoData));
+
+	dest->strategy = src->strategy;
+	ndatums = dest->ndatums = src->ndatums;
+	partnatts = key->partnatts;
+
+	/* Range partitioned table has an extra index. */
+	num_indexes = key->strategy == PARTITION_STRATEGY_RANGE ? ndatums + 1 : ndatums;
+
+	/* List partitioned tables have only a single partition key. */
+	Assert(key->strategy != PARTITION_STRATEGY_LIST || partnatts == 1);
+
+	dest->datums = (Datum **) palloc(sizeof(Datum *) * ndatums);
+
+	if (src->kind != NULL)
+	{
+		dest->kind = (PartitionRangeDatumKind **) palloc(ndatums *
+												sizeof(PartitionRangeDatumKind *));
+		for (i = 0; i < ndatums; i++)
+		{
+			dest->kind[i] = (PartitionRangeDatumKind *) palloc(partnatts *
+												sizeof(PartitionRangeDatumKind));
+
+			memcpy(dest->kind[i], src->kind[i],
+				   sizeof(PartitionRangeDatumKind) * key->partnatts);
+		}
+	}
+	else
+		dest->kind = NULL;
+
+	for (i = 0; i < ndatums; i++)
+	{
+		int		j;
+		dest->datums[i] = (Datum *) palloc(sizeof(Datum) * partnatts);
+
+		for (j = 0; j < partnatts; j++)
+		{
+			if (dest->kind == NULL ||
+				dest->kind[i][j] == PARTITION_RANGE_DATUM_VALUE)
+				dest->datums[i][j] = datumCopy(src->datums[i][j],
+											   key->parttypbyval[j],
+											   key->parttyplen[j]);
+		}
+	}
+
+	dest->indexes = (int *) palloc(sizeof(int) * num_indexes);
+	memcpy(dest->indexes, src->indexes, sizeof(int) * num_indexes);
+
+	dest->null_index = src->null_index;
+	dest->default_index = src->default_index;
+
+	return dest;
+}
+
 /*
  * check_new_partition_bound
  *
diff --git a/src/backend/optimizer/util/plancat.c b/src/backend/optimizer/util/plancat.c
@@ -1825,13 +1825,15 @@ set_relation_partition_info(PlannerInfo *root, RelOptInfo *rel,
 							Relation relation)
 {
 	PartitionDesc partdesc;
+	PartitionKey  partkey;
 
 	Assert(relation->rd_rel->relkind == RELKIND_PARTITIONED_TABLE);
 
 	partdesc = RelationGetPartitionDesc(relation);
+	partkey = RelationGetPartitionKey(relation);
 	rel->part_scheme = find_partition_scheme(root, relation);
 	Assert(partdesc != NULL && rel->part_scheme != NULL);
-	rel->boundinfo = partdesc->boundinfo;
+	rel->boundinfo = partition_bounds_copy(partdesc->boundinfo, partkey);
 	rel->nparts = partdesc->nparts;
 	set_baserel_partition_key_exprs(relation, rel);
 }
@@ -1888,18 +1890,33 @@ find_partition_scheme(PlannerInfo *root, Relation relation)
 
 	/*
 	 * Did not find matching partition scheme. Create one copying relevant
-	 * information from the relcache. Instead of copying whole arrays, copy
-	 * the pointers in relcache. It's safe to do so since
-	 * RelationClearRelation() wouldn't change it while planner is using it.
+	 * information from the relcache. We need to copy the contents of the array
+	 * since the relcache entry may not survive after we have closed the
+	 * relation.
 	 */
 	part_scheme = (PartitionScheme) palloc0(sizeof(PartitionSchemeData));
 	part_scheme->strategy = partkey->strategy;
 	part_scheme->partnatts = partkey->partnatts;
-	part_scheme->partopfamily = partkey->partopfamily;
-	part_scheme->partopcintype = partkey->partopcintype;
-	part_scheme->parttypcoll = partkey->parttypcoll;
-	part_scheme->parttyplen = partkey->parttyplen;
-	part_scheme->parttypbyval = partkey->parttypbyval;
+
+	part_scheme->partopfamily = (Oid *) palloc(sizeof(Oid) * partnatts);
+	memcpy(part_scheme->partopfamily, partkey->partopfamily,
+		   sizeof(Oid) * partnatts);
+
+	part_scheme->partopcintype = (Oid *) palloc(sizeof(Oid) * partnatts);
+	memcpy(part_scheme->partopcintype, partkey->partopcintype,
+		   sizeof(Oid) * partnatts);
+
+	part_scheme->parttypcoll = (Oid *) palloc(sizeof(Oid) * partnatts);
+	memcpy(part_scheme->parttypcoll, partkey->parttypcoll,
+		   sizeof(Oid) * partnatts);
+
+	part_scheme->parttyplen = (int16 *) palloc(sizeof(int16) * partnatts);
+	memcpy(part_scheme->parttyplen, partkey->parttyplen,
+		   sizeof(int16) * partnatts);
+
+	part_scheme->parttypbyval = (bool *) palloc(sizeof(bool) * partnatts);
+	memcpy(part_scheme->parttypbyval, partkey->parttypbyval,
+		   sizeof(bool) * partnatts);
 
 	/* Add the partitioning scheme to PlannerInfo. */
 	root->part_schemes = lappend(root->part_schemes, part_scheme);
diff --git a/src/include/catalog/partition.h b/src/include/catalog/partition.h
@@ -74,6 +74,8 @@ extern void RelationBuildPartitionDesc(Relation relation);
 extern bool partition_bounds_equal(int partnatts, int16 *parttyplen,
 					   bool *parttypbyval, PartitionBoundInfo b1,
 					   PartitionBoundInfo b2);
+extern PartitionBoundInfo partition_bounds_copy(PartitionBoundInfo src,
+					  PartitionKey key);
 
 extern void check_new_partition_bound(char *relname, Relation parent,
 						  PartitionBoundSpec *spec);
