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/dblink.c

@@ -100,7 +100,7 @@ static remoteConn *getConnectionByName(const char *name);
 static HTAB *createConnHash(void);
 static void createNewConnection(const char *name, remoteConn *rconn);
 static void deleteConnection(const char *name);
-static char **get_pkey_attnames(Relation rel, int16 *numatts);
+static char **get_pkey_attnames(Relation rel, int16 *indnkeyatts);
 static char **get_text_array_contents(ArrayType *array, int *numitems);
 static char *get_sql_insert(Relation rel, int *pkattnums, int pknumatts, char **src_pkattvals, char **tgt_pkattvals);
 static char *get_sql_delete(Relation rel, int *pkattnums, int pknumatts, char **tgt_pkattvals);
@@ -1493,7 +1493,7 @@ PG_FUNCTION_INFO_V1(dblink_get_pkey);
 Datum
 dblink_get_pkey(PG_FUNCTION_ARGS)
 {
-	int16		numatts;
+	int16		indnkeyatts;
 	char	  **results;
 	FuncCallContext *funcctx;
 	int32		call_cntr;
@@ -1519,7 +1519,7 @@ dblink_get_pkey(PG_FUNCTION_ARGS)
 		rel = get_rel_from_relname(PG_GETARG_TEXT_PP(0), AccessShareLock, ACL_SELECT);
 
 		/* get the array of attnums */
-		results = get_pkey_attnames(rel, &numatts);
+		results = get_pkey_attnames(rel, &indnkeyatts);
 
 		relation_close(rel, AccessShareLock);
 
@@ -1539,9 +1539,9 @@ dblink_get_pkey(PG_FUNCTION_ARGS)
 		attinmeta = TupleDescGetAttInMetadata(tupdesc);
 		funcctx->attinmeta = attinmeta;
 
-		if ((results != NULL) && (numatts > 0))
+		if ((results != NULL) && (indnkeyatts > 0))
 		{
-			funcctx->max_calls = numatts;
+			funcctx->max_calls = indnkeyatts;
 
 			/* got results, keep track of them */
 			funcctx->user_fctx = results;
@@ -2029,10 +2029,10 @@ dblink_fdw_validator(PG_FUNCTION_ARGS)
  * get_pkey_attnames
  *
  * Get the primary key attnames for the given relation.
- * Return NULL, and set numatts = 0, if no primary key exists.
+ * Return NULL, and set indnkeyatts = 0, if no primary key exists.
  */
 static char **
-get_pkey_attnames(Relation rel, int16 *numatts)
+get_pkey_attnames(Relation rel, int16 *indnkeyatts)
 {
 	Relation	indexRelation;
 	ScanKeyData skey;
@@ -2042,8 +2042,8 @@ get_pkey_attnames(Relation rel, int16 *numatts)
 	char	  **result = NULL;
 	TupleDesc	tupdesc;
 
-	/* initialize numatts to 0 in case no primary key exists */
-	*numatts = 0;
+	/* initialize indnkeyatts to 0 in case no primary key exists */
+	*indnkeyatts = 0;
 
 	tupdesc = rel->rd_att;
 
@@ -2064,12 +2064,12 @@ get_pkey_attnames(Relation rel, int16 *numatts)
 		/* we're only interested if it is the primary key */
 		if (index->indisprimary)
 		{
-			*numatts = index->indnatts;
-			if (*numatts > 0)
+			*indnkeyatts = index->indnkeyatts;
+			if (*indnkeyatts > 0)
 			{
-				result = (char **) palloc(*numatts * sizeof(char *));
+				result = (char **) palloc(*indnkeyatts * sizeof(char *));
 
-				for (i = 0; i < *numatts; i++)
+				for (i = 0; i < *indnkeyatts; i++)
 					result[i] = SPI_fname(tupdesc, index->indkey.values[i]);
 			}
 			break;

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));

contrib/dblink/sql/dblink.sql

@@ -38,6 +38,44 @@ 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}"}');
 
+-- 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');
+
+-- 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"}');
+-- 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}"}');
+
+-- 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"}');
+-- 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}"}');
+
+-- build a delete statement based on a local tuple,
+SELECT dblink_build_sql_delete('foo_1','1 2',2,'{"0", "a"}');
+-- too many pk fields, should fail
+SELECT dblink_build_sql_delete('foo_1','1 2 3 4',4,'{"0", "a", "{a0,b0,c0}"}');
+
+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));