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

contrib/dblink/expected/dblink.out

@@ -54,6 +54,61 @@ SELECT dblink_build_sql_delete('foo','1 2',2,'{"0", "a"}');
 -- too many pk fields, should fail
 SELECT dblink_build_sql_delete('foo','1 2 3 4',4,'{"0", "a", "{a0,b0,c0}"}');
 ERROR:  invalid attribute number 4
+-- repeat the test for table with primary key index with included columns
+CREATE TABLE foo_1(f1 int, f2 text, f3 text[], primary key (f1,f2) include (f3));
+INSERT INTO foo_1 VALUES (0,'a','{"a0","b0","c0"}');
+INSERT INTO foo_1 VALUES (1,'b','{"a1","b1","c1"}');
+INSERT INTO foo_1 VALUES (2,'c','{"a2","b2","c2"}');
+INSERT INTO foo_1 VALUES (3,'d','{"a3","b3","c3"}');
+INSERT INTO foo_1 VALUES (4,'e','{"a4","b4","c4"}');
+INSERT INTO foo_1 VALUES (5,'f','{"a5","b5","c5"}');
+INSERT INTO foo_1 VALUES (6,'g','{"a6","b6","c6"}');
+INSERT INTO foo_1 VALUES (7,'h','{"a7","b7","c7"}');
+INSERT INTO foo_1 VALUES (8,'i','{"a8","b8","c8"}');
+INSERT INTO foo_1 VALUES (9,'j','{"a9","b9","c9"}');
+-- misc utilities
+-- list the primary key fields
+SELECT *
+FROM dblink_get_pkey('foo_1');
+ position | colname 
+----------+---------
+        1 | f1
+        2 | f2
+(2 rows)
+
+-- build an insert statement based on a local tuple,
+-- replacing the primary key values with new ones
+SELECT dblink_build_sql_insert('foo_1','1 2',2,'{"0", "a"}','{"99", "xyz"}');
+                   dblink_build_sql_insert                   
+-------------------------------------------------------------
+ INSERT INTO foo_1(f1,f2,f3) VALUES('99','xyz','{a0,b0,c0}')
+(1 row)
+
+-- too many pk fields, should fail
+SELECT dblink_build_sql_insert('foo_1','1 2 3 4',4,'{"0", "a", "{a0,b0,c0}"}','{"99", "xyz", "{za0,zb0,zc0}"}');
+ERROR:  invalid attribute number 4
+-- build an update statement based on a local tuple,
+-- replacing the primary key values with new ones
+SELECT dblink_build_sql_update('foo_1','1 2',2,'{"0", "a"}','{"99", "xyz"}');
+                                 dblink_build_sql_update                                  
+------------------------------------------------------------------------------------------
+ UPDATE foo_1 SET f1 = '99', f2 = 'xyz', f3 = '{a0,b0,c0}' WHERE f1 = '99' AND f2 = 'xyz'
+(1 row)
+
+-- too many pk fields, should fail
+SELECT dblink_build_sql_update('foo_1','1 2 3 4',4,'{"0", "a", "{a0,b0,c0}"}','{"99", "xyz", "{za0,zb0,zc0}"}');
+ERROR:  invalid attribute number 4
+-- build a delete statement based on a local tuple,
+SELECT dblink_build_sql_delete('foo_1','1 2',2,'{"0", "a"}');
+            dblink_build_sql_delete            
+-----------------------------------------------
+ DELETE FROM foo_1 WHERE f1 = '0' AND f2 = 'a'
+(1 row)
+
+-- too many pk fields, should fail
+SELECT dblink_build_sql_delete('foo_1','1 2 3 4',4,'{"0", "a", "{a0,b0,c0}"}');
+ERROR:  invalid attribute number 4
+DROP TABLE foo_1;
 -- retest using a quoted and schema qualified table
 CREATE SCHEMA "MySchema";
 CREATE TABLE "MySchema"."Foo"(f1 int, f2 text, f3 text[], primary key (f1,f2));