Add index-only scan support to range type GiST opclass.

Andreas Karlsson

src/backend/utils/adt/rangetypes_gist.c

@@ -216,7 +216,7 @@ range_gist_union(PG_FUNCTION_ARGS)
 	PG_RETURN_RANGE(result_range);
 }
 
-/* compress, decompress are no-ops */
+/* compress, decompress, fetch are no-ops */
 Datum
 range_gist_compress(PG_FUNCTION_ARGS)
 {
@@ -233,6 +233,14 @@ range_gist_decompress(PG_FUNCTION_ARGS)
 	PG_RETURN_POINTER(entry);
 }
 
+Datum
+range_gist_fetch(PG_FUNCTION_ARGS)
+{
+	GISTENTRY  *entry = (GISTENTRY *) PG_GETARG_POINTER(0);
+
+	PG_RETURN_POINTER(entry);
+}
+
 /*
  * GiST page split penalty function.
  *

src/include/catalog/catversion.h

@@ -53,6 +53,6 @@
  */
 
 /*							yyyymmddN */
-#define CATALOG_VERSION_NO	201503281
+#define CATALOG_VERSION_NO	201503301
 
 #endif

src/include/catalog/pg_amproc.h

@@ -235,6 +235,7 @@ DATA(insert (	3919   3831 3831 4 3878 ));
 DATA(insert (	3919   3831 3831 5 3879 ));
 DATA(insert (	3919   3831 3831 6 3880 ));
 DATA(insert (	3919   3831 3831 7 3881 ));
+DATA(insert (	3919   3831 3831 9 3996 ));
 
 
 /* gin */

src/include/catalog/pg_proc.h

@@ -4951,6 +4951,8 @@ DATA(insert OID = 3877 (  range_gist_compress	PGNSP PGUID 12 1 0 0 0 f f f f t f
 DESCR("GiST support");
 DATA(insert OID = 3878 (  range_gist_decompress PGNSP PGUID 12 1 0 0 0 f f f f t f i 1 0 2281 "2281" _null_ _null_ _null_ _null_ range_gist_decompress _null_ _null_ _null_ ));
 DESCR("GiST support");
+DATA(insert OID = 3996 (  range_gist_fetch		PGNSP PGUID 12 1 0 0 0 f f f f t f i 1 0 2281 "2281" _null_ _null_ _null_ _null_ range_gist_fetch _null_ _null_ _null_ ));
+DESCR("GiST support");
 DATA(insert OID = 3879 (  range_gist_penalty	PGNSP PGUID 12 1 0 0 0 f f f f t f i 3 0 2281 "2281 2281 2281" _null_ _null_ _null_ _null_ range_gist_penalty _null_ _null_ _null_ ));
 DESCR("GiST support");
 DATA(insert OID = 3880 (  range_gist_picksplit	PGNSP PGUID 12 1 0 0 0 f f f f t f i 2 0 2281 "2281 2281" _null_ _null_ _null_ _null_ range_gist_picksplit _null_ _null_ _null_ ));

src/include/utils/rangetypes.h

@@ -209,6 +209,7 @@ extern RangeType *make_empty_range(TypeCacheEntry *typcache);
 extern Datum range_gist_consistent(PG_FUNCTION_ARGS);
 extern Datum range_gist_compress(PG_FUNCTION_ARGS);
 extern Datum range_gist_decompress(PG_FUNCTION_ARGS);
+extern Datum range_gist_fetch(PG_FUNCTION_ARGS);
 extern Datum range_gist_union(PG_FUNCTION_ARGS);
 extern Datum range_gist_penalty(PG_FUNCTION_ARGS);
 extern Datum range_gist_picksplit(PG_FUNCTION_ARGS);

src/test/regress/expected/rangetypes.out

@@ -1072,6 +1072,25 @@ select count(*) from test_range_spgist where ir -|- int4range(100,500);
      5
 (1 row)
 
+-- test index-only scans
+explain (costs off)
+select ir from test_range_spgist where ir -|- int4range(10,20) order by ir;
+                               QUERY PLAN                               
+------------------------------------------------------------------------
+ Sort
+   Sort Key: ir
+   ->  Index Only Scan using test_range_spgist_idx on test_range_spgist
+         Index Cond: (ir -|- '[10,20)'::int4range)
+(4 rows)
+
+select ir from test_range_spgist where ir -|- int4range(10,20) order by ir;
+     ir     
+------------
+ [20,30)
+ [20,30)
+ [20,10020)
+(3 rows)
+
 RESET enable_seqscan;
 RESET enable_indexscan;
 RESET enable_bitmapscan;

src/test/regress/sql/rangetypes.sql

@@ -286,6 +286,11 @@ select count(*) from test_range_spgist where ir &< int4range(100,500);
 select count(*) from test_range_spgist where ir &> int4range(100,500);
 select count(*) from test_range_spgist where ir -|- int4range(100,500);
 
+-- test index-only scans
+explain (costs off)
+select ir from test_range_spgist where ir -|- int4range(10,20) order by ir;
+select ir from test_range_spgist where ir -|- int4range(10,20) order by ir;
+
 RESET enable_seqscan;
 RESET enable_indexscan;
 RESET enable_bitmapscan;