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, 31 insertions, 0 deletions

diff --git a/src/backend/utils/adt/ruleutils.c b/src/backend/utils/adt/ruleutils.c
index f8fc7f83f9b..b75a224ee8c 100644
--- a/src/backend/utils/adt/ruleutils.c
+++ b/src/backend/utils/adt/ruleutils.c
@@ -1296,6 +1296,21 @@ pg_get_indexdef_worker(Oid indexrelid, int colno,
 		Oid			keycoltype;
 		Oid			keycolcollation;
 
+		/*
+		 * attrsOnly flag is used for building unique-constraint and
+		 * exclusion-constraint error messages. Included attrs are meaningless
+		 * there, so do not include them in the message.
+		 */
+		if (attrsOnly && keyno >= idxrec->indnkeyatts)
+			break;
+
+		/* Report the INCLUDED attributes, if any. */
+		if ((!attrsOnly) && keyno == idxrec->indnkeyatts)
+		{
+			appendStringInfoString(&buf, ") INCLUDE (");
+			sep = "";
+		}
+
 		if (!colno)
 			appendStringInfoString(&buf, sep);
 		sep = ", ";
@@ -1347,6 +1362,9 @@ pg_get_indexdef_worker(Oid indexrelid, int colno,
 				appendStringInfo(&buf, " COLLATE %s",
 								 generate_collation_name((indcoll)));
 
+			if (keyno >= idxrec->indnkeyatts)
+				continue;
+
 			/* Add the operator class name, if not default */
 			get_opclass_name(indclass->values[keyno], keycoltype, &buf);
 
@@ -2047,6 +2065,19 @@ pg_get_constraintdef_worker(Oid constraintId, bool fullCommand,
 
 				appendStringInfoChar(&buf, ')');
 
+				/* Fetch and build including column list */
+				isnull = true;
+				val = SysCacheGetAttr(CONSTROID, tup,
+									  Anum_pg_constraint_conincluding, &isnull);
+				if (!isnull)
+				{
+					appendStringInfoString(&buf, " INCLUDE (");
+
+					decompile_column_index_array(val, conForm->conrelid, &buf);
+
+					appendStringInfoChar(&buf, ')');
+				}
+
 				indexId = get_constraint_index(constraintId);
 
 				/* XXX why do we only print these bits if fullCommand? */