Indexes with INCLUDE columns and their support in B-tree

This patch introduces INCLUDE clause to index definition.  This clause
specifies a list of columns which will be included as a non-key part in
the index.  The INCLUDE columns exist solely to allow more queries to
benefit from index-only scans.  Also, such columns don't need to have
appropriate operator classes.  Expressions are not supported as INCLUDE
columns since they cannot be used in index-only scans.

Index access methods supporting INCLUDE are indicated by amcaninclude flag
in IndexAmRoutine.  For now, only B-tree indexes support INCLUDE clause.

In B-tree indexes INCLUDE columns are truncated from pivot index tuples
(tuples located in non-leaf pages and high keys).  Therefore, B-tree indexes
now might have variable number of attributes.  This patch also provides
generic facility to support that: pivot tuples contain number of their
attributes in t_tid.ip_posid.  Free 13th bit of t_info is used for indicating
that.  This facility will simplify further support of index suffix truncation.
The changes of above are backward-compatible, pg_upgrade doesn't need special
handling of B-tree indexes for that.

Bump catalog version

Author: Anastasia Lubennikova with contribition by Alexander Korotkov and me
Reviewed by: Peter Geoghegan, Tomas Vondra, Antonin Houska, Jeff Janes,
			 David Rowley, Alexander Korotkov
Discussion: https://www.postgresql.org/message-id/flat/56168952.4010101@postgrespro.ru

1 files changed, 5 insertions, 4 deletions

diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index 801db12bee7..846811d1b8e 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -5942,7 +5942,7 @@ ATExecDropNotNull(Relation rel, const char *colName, LOCKMODE lockmode)
 			 * Loop over each attribute in the primary key and see if it
 			 * matches the to-be-altered attribute
 			 */
-			for (i = 0; i < indexStruct->indnatts; i++)
+			for (i = 0; i < indexStruct->indnkeyatts; i++)
 			{
 				if (indexStruct->indkey.values[i] == attnum)
 					ereport(ERROR,
@@ -7641,6 +7641,7 @@ ATAddForeignKeyConstraint(List **wqueue, AlteredTableInfo *tab, Relation rel,
 									  RelationGetRelid(rel),
 									  fkattnum,
 									  numfks,
+									  numfks,
 									  InvalidOid,	/* not a domain constraint */
 									  indexOid,
 									  RelationGetRelid(pkrel),
@@ -8199,7 +8200,7 @@ transformFkeyGetPrimaryKey(Relation pkrel, Oid *indexOid,
 	 * assume a primary key cannot have expressional elements)
 	 */
 	*attnamelist = NIL;
-	for (i = 0; i < indexStruct->indnatts; i++)
+	for (i = 0; i < indexStruct->indnkeyatts; i++)
 	{
 		int			pkattno = indexStruct->indkey.values[i];
 
@@ -8277,7 +8278,7 @@ transformFkeyCheckAttrs(Relation pkrel,
 		 * partial index; forget it if there are any expressions, too. Invalid
 		 * indexes are out as well.
 		 */
-		if (indexStruct->indnatts == numattrs &&
+		if (indexStruct->indnkeyatts == numattrs &&
 			indexStruct->indisunique &&
 			IndexIsValid(indexStruct) &&
 			heap_attisnull(indexTuple, Anum_pg_index_indpred, NULL) &&
@@ -12529,7 +12530,7 @@ ATExecReplicaIdentity(Relation rel, ReplicaIdentityStmt *stmt, LOCKMODE lockmode
 						RelationGetRelationName(indexRel))));
 
 	/* Check index for nullable columns. */
-	for (key = 0; key < indexRel->rd_index->indnatts; key++)
+	for (key = 0; key < IndexRelationGetNumberOfKeyAttributes(indexRel); key++)
 	{
 		int16		attno = indexRel->rd_index->indkey.values[key];
 		Form_pg_attribute attr;