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, 7 insertions, 7 deletions

diff --git a/src/backend/executor/execIndexing.c b/src/backend/executor/execIndexing.c
index 62e51f1ef3b..903076ee3c4 100644
--- a/src/backend/executor/execIndexing.c
+++ b/src/backend/executor/execIndexing.c
@@ -648,7 +648,7 @@ check_exclusion_or_unique_constraint(Relation heap, Relation index,
 	Oid		   *constr_procs;
 	uint16	   *constr_strats;
 	Oid		   *index_collations = index->rd_indcollation;
-	int			index_natts = index->rd_index->indnatts;
+	int			indnkeyatts = IndexRelationGetNumberOfKeyAttributes(index);
 	IndexScanDesc index_scan;
 	HeapTuple	tup;
 	ScanKeyData scankeys[INDEX_MAX_KEYS];
@@ -675,7 +675,7 @@ check_exclusion_or_unique_constraint(Relation heap, Relation index,
 	 * If any of the input values are NULL, the constraint check is assumed to
 	 * pass (i.e., we assume the operators are strict).
 	 */
-	for (i = 0; i < index_natts; i++)
+	for (i = 0; i < indnkeyatts; i++)
 	{
 		if (isnull[i])
 			return true;
@@ -687,7 +687,7 @@ check_exclusion_or_unique_constraint(Relation heap, Relation index,
 	 */
 	InitDirtySnapshot(DirtySnapshot);
 
-	for (i = 0; i < index_natts; i++)
+	for (i = 0; i < indnkeyatts; i++)
 	{
 		ScanKeyEntryInitialize(&scankeys[i],
 							   0,
@@ -719,8 +719,8 @@ check_exclusion_or_unique_constraint(Relation heap, Relation index,
 retry:
 	conflict = false;
 	found_self = false;
-	index_scan = index_beginscan(heap, index, &DirtySnapshot, index_natts, 0);
-	index_rescan(index_scan, scankeys, index_natts, NULL, 0);
+	index_scan = index_beginscan(heap, index, &DirtySnapshot, indnkeyatts, 0);
+	index_rescan(index_scan, scankeys, indnkeyatts, NULL, 0);
 
 	while ((tup = index_getnext(index_scan,
 								ForwardScanDirection)) != NULL)
@@ -881,10 +881,10 @@ index_recheck_constraint(Relation index, Oid *constr_procs,
 						 Datum *existing_values, bool *existing_isnull,
 						 Datum *new_values)
 {
-	int			index_natts = index->rd_index->indnatts;
+	int			indnkeyatts = IndexRelationGetNumberOfKeyAttributes(index);
 	int			i;
 
-	for (i = 0; i < index_natts; i++)
+	for (i = 0; i < indnkeyatts; i++)
 	{
 		/* Assume the exclusion operators are strict */
 		if (existing_isnull[i])