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

4 files changed, 6 insertions, 5 deletions

diff --git a/src/test/isolation/specs/insert-conflict-do-nothing-2.spec b/src/test/isolation/specs/insert-conflict-do-nothing-2.spec
index f1e5bde357c..8a8ec944473 100644
--- a/src/test/isolation/specs/insert-conflict-do-nothing-2.spec
+++ b/src/test/isolation/specs/insert-conflict-do-nothing-2.spec
@@ -3,7 +3,7 @@
 
 setup
 {
-  CREATE TABLE ints (key int primary key, val text);
+  CREATE TABLE ints (key int, val text, PRIMARY KEY (key) INCLUDE (val));
 }
 
 teardown
diff --git a/src/test/isolation/specs/insert-conflict-do-update-2.spec b/src/test/isolation/specs/insert-conflict-do-update-2.spec
index cd7e3f42feb..f5b4f601b58 100644
--- a/src/test/isolation/specs/insert-conflict-do-update-2.spec
+++ b/src/test/isolation/specs/insert-conflict-do-update-2.spec
@@ -7,7 +7,7 @@
 setup
 {
   CREATE TABLE upsert (key text not null, payload text);
-  CREATE UNIQUE INDEX ON upsert(lower(key));
+  CREATE UNIQUE INDEX ON upsert(lower(key)) INCLUDE (payload);
 }
 
 teardown
diff --git a/src/test/isolation/specs/lock-committed-keyupdate.spec b/src/test/isolation/specs/lock-committed-keyupdate.spec
index 1630282d0f4..3fb424af0ed 100644
--- a/src/test/isolation/specs/lock-committed-keyupdate.spec
+++ b/src/test/isolation/specs/lock-committed-keyupdate.spec
@@ -8,7 +8,7 @@
 setup
 {
     DROP TABLE IF EXISTS lcku_table;
-    CREATE TABLE lcku_table (id INTEGER PRIMARY KEY, value TEXT);
+    CREATE TABLE lcku_table (id INTEGER, value TEXT, PRIMARY KEY (id) INCLUDE (value));
     INSERT INTO lcku_table VALUES (1, 'one');
     INSERT INTO lcku_table VALUES (3, 'two');
 }
diff --git a/src/test/isolation/specs/lock-update-traversal.spec b/src/test/isolation/specs/lock-update-traversal.spec
index 7042b9399cf..2ffe87d152b 100644
--- a/src/test/isolation/specs/lock-update-traversal.spec
+++ b/src/test/isolation/specs/lock-update-traversal.spec
@@ -7,8 +7,9 @@
 setup
 {
   CREATE TABLE foo (
-	key		int PRIMARY KEY,
-	value	int
+	key		int,
+	value	int,
+	PRIMARY KEY (key) INCLUDE (value)
   );
 
   INSERT INTO foo VALUES (1, 1);