CREATE INDEX ... INCLUDING (column[, ...])

Now indexes (but only B-tree for now) can contain "extra" column(s) which
doesn't participate in index structure, they are just stored in leaf
tuples. It allows to use index only scan by using single index instead
of two or more indexes.

Author: Anastasia Lubennikova with minor editorializing by me
Reviewers: David Rowley, Peter Geoghegan, Jeff Janes

1 files changed, 9 insertions, 7 deletions

diff --git a/src/backend/access/index/genam.c b/src/backend/access/index/genam.c
index 65c941d812c..de5781458e3 100644
--- a/src/backend/access/index/genam.c
+++ b/src/backend/access/index/genam.c
@@ -174,13 +174,15 @@ BuildIndexValueDescription(Relation indexRelation,
 	StringInfoData buf;
 	Form_pg_index idxrec;
 	HeapTuple	ht_idx;
-	int			natts = indexRelation->rd_rel->relnatts;
+	int			indnkeyatts;
 	int			i;
 	int			keyno;
 	Oid			indexrelid = RelationGetRelid(indexRelation);
 	Oid			indrelid;
 	AclResult	aclresult;
 
+	indnkeyatts = IndexRelationGetNumberOfKeyAttributes(indexRelation);
+
 	/*
 	 * Check permissions- if the user does not have access to view all of the
 	 * key columns then return NULL to avoid leaking data.
@@ -218,7 +220,7 @@ BuildIndexValueDescription(Relation indexRelation,
 		 * No table-level access, so step through the columns in the index and
 		 * make sure the user has SELECT rights on all of them.
 		 */
-		for (keyno = 0; keyno < idxrec->indnatts; keyno++)
+		for (keyno = 0; keyno < idxrec->indnkeyatts; keyno++)
 		{
 			AttrNumber	attnum = idxrec->indkey.values[keyno];
 
@@ -244,7 +246,7 @@ BuildIndexValueDescription(Relation indexRelation,
 	appendStringInfo(&buf, "(%s)=(",
 					 pg_get_indexdef_columns(indexrelid, true));
 
-	for (i = 0; i < natts; i++)
+	for (i = 0; i < indnkeyatts; i++)
 	{
 		char	   *val;
 
@@ -362,7 +364,7 @@ systable_beginscan(Relation heapRelation,
 		{
 			int			j;
 
-			for (j = 0; j < irel->rd_index->indnatts; j++)
+			for (j = 0; j < IndexRelationGetNumberOfAttributes(irel); j++)
 			{
 				if (key[i].sk_attno == irel->rd_index->indkey.values[j])
 				{
@@ -370,7 +372,7 @@ systable_beginscan(Relation heapRelation,
 					break;
 				}
 			}
-			if (j == irel->rd_index->indnatts)
+			if (j == IndexRelationGetNumberOfAttributes(irel))
 				elog(ERROR, "column is not in index");
 		}
 
@@ -564,7 +566,7 @@ systable_beginscan_ordered(Relation heapRelation,
 	{
 		int			j;
 
-		for (j = 0; j < indexRelation->rd_index->indnatts; j++)
+		for (j = 0; j < IndexRelationGetNumberOfAttributes(indexRelation); j++)
 		{
 			if (key[i].sk_attno == indexRelation->rd_index->indkey.values[j])
 			{
@@ -572,7 +574,7 @@ systable_beginscan_ordered(Relation heapRelation,
 				break;
 			}
 		}
-		if (j == indexRelation->rd_index->indnatts)
+		if (j == IndexRelationGetNumberOfAttributes(indexRelation))
 			elog(ERROR, "column is not in index");
 	}