Add index-only scan support to btree_gist.

inet, cidr, and timetz indexes still cannot support index-only scans,
because they don't store the original unmodified value in the index, but a
derived approximate value.

20 files changed, 164 insertions, 21 deletions

diff --git a/contrib/btree_gist/expected/bit.out b/contrib/btree_gist/expected/bit.out
index ae823046002..8606baf366e 100644
--- a/contrib/btree_gist/expected/bit.out
+++ b/contrib/btree_gist/expected/bit.out
@@ -64,3 +64,13 @@ SELECT count(*) FROM bittmp WHERE a >   '011011000100010111011000110000100';
    350
 (1 row)
 
+-- Test index-only scans
+SET enable_bitmapscan=off;
+EXPLAIN (COSTS OFF)
+SELECT a FROM bittmp WHERE a BETWEEN '1000000' and '1000001';
+                              QUERY PLAN                               
+-----------------------------------------------------------------------
+ Index Only Scan using bitidx on bittmp
+   Index Cond: ((a >= B'1000000'::"bit") AND (a <= B'1000001'::"bit"))
+(2 rows)
+
diff --git a/contrib/btree_gist/expected/bytea.out b/contrib/btree_gist/expected/bytea.out
index 917fac18125..b9efa73c085 100644
--- a/contrib/btree_gist/expected/bytea.out
+++ b/contrib/btree_gist/expected/bytea.out
@@ -71,3 +71,20 @@ SELECT count(*) FROM byteatmp WHERE a  =  '2eb2c961c1cbf6 cf8d7b68cb9a2f36 7bbed
      1
 (1 row)
 
+-- Test index-only scans
+SET enable_bitmapscan=off;
+EXPLAIN (COSTS OFF)
+SELECT a FROM byteatmp where a > 'ffa'::bytea;
+                 QUERY PLAN                 
+--------------------------------------------
+ Index Only Scan using byteaidx on byteatmp
+   Index Cond: (a > '\x666661'::bytea)
+(2 rows)
+
+SELECT a FROM byteatmp where a > 'ffa'::bytea;
+               a                
+--------------------------------
+ \x666662656532373363376262
+ \x6666626663313331336339633835
+(2 rows)
+
diff --git a/contrib/btree_gist/expected/cash.out b/contrib/btree_gist/expected/cash.out
index a4100d844e7..cacbd718541 100644
--- a/contrib/btree_gist/expected/cash.out
+++ b/contrib/btree_gist/expected/cash.out
@@ -74,10 +74,10 @@ SELECT count(*) FROM moneytmp WHERE a >  '22649.64'::money;
 
 EXPLAIN (COSTS OFF)
 SELECT a, a <-> '21472.79' FROM moneytmp ORDER BY a <-> '21472.79' LIMIT 3;
-                  QUERY PLAN                   
------------------------------------------------
+                    QUERY PLAN                    
+--------------------------------------------------
  Limit
-   ->  Index Scan using moneyidx on moneytmp
+   ->  Index Only Scan using moneyidx on moneytmp
          Order By: (a <-> '$21,472.79'::money)
 (3 rows)
 
diff --git a/contrib/btree_gist/expected/char.out b/contrib/btree_gist/expected/char.out
index 5260995a755..d715c045cc1 100644
--- a/contrib/btree_gist/expected/char.out
+++ b/contrib/btree_gist/expected/char.out
@@ -64,3 +64,19 @@ SELECT count(*) FROM chartmp WHERE a >   '31b0'::char(32);
    400
 (1 row)
 
+-- Test index-only scans
+SET enable_bitmapscan=off;
+EXPLAIN (COSTS OFF)
+SELECT * FROM chartmp WHERE a BETWEEN '31a' AND '31c';
+                          QUERY PLAN                           
+---------------------------------------------------------------
+ Index Only Scan using charidx on chartmp
+   Index Cond: ((a >= '31a'::bpchar) AND (a <= '31c'::bpchar))
+(2 rows)
+
+SELECT * FROM chartmp WHERE a BETWEEN '31a' AND '31c';
+  a   
+------
+ 31b0
+(1 row)
+
diff --git a/contrib/btree_gist/expected/char_1.out b/contrib/btree_gist/expected/char_1.out
index a1d24876d8a..867318002b8 100644
--- a/contrib/btree_gist/expected/char_1.out
+++ b/contrib/btree_gist/expected/char_1.out
@@ -64,3 +64,19 @@ SELECT count(*) FROM chartmp WHERE a >   '31b0'::char(32);
    214
 (1 row)
 
+-- Test index-only scans
+SET enable_bitmapscan=off;
+EXPLAIN (COSTS OFF)
+SELECT * FROM chartmp WHERE a BETWEEN '31a' AND '31c';
+                          QUERY PLAN                           
+---------------------------------------------------------------
+ Index Only Scan using charidx on chartmp
+   Index Cond: ((a >= '31a'::bpchar) AND (a <= '31c'::bpchar))
+(2 rows)
+
+SELECT * FROM chartmp WHERE a BETWEEN '31a' AND '31c';
+  a   
+------
+ 31b0
+(1 row)
+
diff --git a/contrib/btree_gist/expected/date.out b/contrib/btree_gist/expected/date.out
index 4a360bea6d6..5db864bb82c 100644
--- a/contrib/btree_gist/expected/date.out
+++ b/contrib/btree_gist/expected/date.out
@@ -74,10 +74,10 @@ SELECT count(*) FROM datetmp WHERE a >  '2001-02-13'::date;
 
 EXPLAIN (COSTS OFF)
 SELECT a, a <-> '2001-02-13' FROM datetmp ORDER BY a <-> '2001-02-13' LIMIT 3;
-                  QUERY PLAN                  
-----------------------------------------------
+                   QUERY PLAN                   
+------------------------------------------------
  Limit
-   ->  Index Scan using dateidx on datetmp
+   ->  Index Only Scan using dateidx on datetmp
          Order By: (a <-> '02-13-2001'::date)
 (3 rows)
 
diff --git a/contrib/btree_gist/expected/float4.out b/contrib/btree_gist/expected/float4.out
index 1695f7805a0..4a52a9399a5 100644
--- a/contrib/btree_gist/expected/float4.out
+++ b/contrib/btree_gist/expected/float4.out
@@ -74,10 +74,10 @@ SELECT count(*) FROM float4tmp WHERE a >  -179.0::float4;
 
 EXPLAIN (COSTS OFF)
 SELECT a, a <-> '-179.0' FROM float4tmp ORDER BY a <-> '-179.0' LIMIT 3;
-                  QUERY PLAN                   
------------------------------------------------
+                     QUERY PLAN                     
+----------------------------------------------------
  Limit
-   ->  Index Scan using float4idx on float4tmp
+   ->  Index Only Scan using float4idx on float4tmp
          Order By: (a <-> (-179)::real)
 (3 rows)
 
diff --git a/contrib/btree_gist/expected/float8.out b/contrib/btree_gist/expected/float8.out
index 7d2228b7973..918d84860f5 100644
--- a/contrib/btree_gist/expected/float8.out
+++ b/contrib/btree_gist/expected/float8.out
@@ -77,7 +77,7 @@ SELECT a, a <-> '-1890.0' FROM float8tmp ORDER BY a <-> '-1890.0' LIMIT 3;
                      QUERY PLAN                      
 -----------------------------------------------------
  Limit
-   ->  Index Scan using float8idx on float8tmp
+   ->  Index Only Scan using float8idx on float8tmp
          Order By: (a <-> (-1890)::double precision)
 (3 rows)
 
diff --git a/contrib/btree_gist/expected/int2.out b/contrib/btree_gist/expected/int2.out
index b1cc3b14b25..711e2c722ac 100644
--- a/contrib/btree_gist/expected/int2.out
+++ b/contrib/btree_gist/expected/int2.out
@@ -74,10 +74,10 @@ SELECT count(*) FROM int2tmp WHERE a >  237::int2;
 
 EXPLAIN (COSTS OFF)
 SELECT a, a <-> '237' FROM int2tmp ORDER BY a <-> '237' LIMIT 3;
-                QUERY PLAN                 
--------------------------------------------
+                   QUERY PLAN                   
+------------------------------------------------
  Limit
-   ->  Index Scan using int2idx on int2tmp
+   ->  Index Only Scan using int2idx on int2tmp
          Order By: (a <-> 237::smallint)
 (3 rows)
 
diff --git a/contrib/btree_gist/expected/int4.out b/contrib/btree_gist/expected/int4.out
index 41bed1f6e34..6bbdc7c3f4b 100644
--- a/contrib/btree_gist/expected/int4.out
+++ b/contrib/btree_gist/expected/int4.out
@@ -74,10 +74,10 @@ SELECT count(*) FROM int4tmp WHERE a >  237::int4;
 
 EXPLAIN (COSTS OFF)
 SELECT a, a <-> '237' FROM int4tmp ORDER BY a <-> '237' LIMIT 3;
-                QUERY PLAN                 
--------------------------------------------
+                   QUERY PLAN                   
+------------------------------------------------
  Limit
-   ->  Index Scan using int4idx on int4tmp
+   ->  Index Only Scan using int4idx on int4tmp
          Order By: (a <-> 237)
 (3 rows)
 
diff --git a/contrib/btree_gist/expected/int8.out b/contrib/btree_gist/expected/int8.out
index ff0af4a5fb8..55982ee3b5c 100644
--- a/contrib/btree_gist/expected/int8.out
+++ b/contrib/btree_gist/expected/int8.out
@@ -77,7 +77,7 @@ SELECT a, a <-> '464571291354841' FROM int8tmp ORDER BY a <-> '464571291354841'
                     QUERY PLAN                     
 ---------------------------------------------------
  Limit
-   ->  Index Scan using int8idx on int8tmp
+   ->  Index Only Scan using int8idx on int8tmp
          Order By: (a <-> 464571291354841::bigint)
 (3 rows)
 
diff --git a/contrib/btree_gist/expected/interval.out b/contrib/btree_gist/expected/interval.out
index 6955251a045..875380978e9 100644
--- a/contrib/btree_gist/expected/interval.out
+++ b/contrib/btree_gist/expected/interval.out
@@ -77,7 +77,7 @@ SELECT a, a <-> '199 days 21:21:23' FROM intervaltmp ORDER BY a <-> '199 days 21
                                 QUERY PLAN                                 
 ---------------------------------------------------------------------------
  Limit
-   ->  Index Scan using intervalidx on intervaltmp
+   ->  Index Only Scan using intervalidx on intervaltmp
          Order By: (a <-> '@ 199 days 21 hours 21 mins 23 secs'::interval)
 (3 rows)
 
diff --git a/contrib/btree_gist/expected/macaddr.out b/contrib/btree_gist/expected/macaddr.out
index 3f0271bd253..c0a4c6287f3 100644
--- a/contrib/btree_gist/expected/macaddr.out
+++ b/contrib/btree_gist/expected/macaddr.out
@@ -64,3 +64,26 @@ SELECT count(*) FROM macaddrtmp WHERE a >  '22:00:5c:e5:9b:0d'::macaddr;
    540
 (1 row)
 
+-- Test index-only scans
+SET enable_bitmapscan=off;
+EXPLAIN (COSTS OFF)
+SELECT * FROM macaddrtmp WHERE a < '02:03:04:05:06:07'::macaddr;
+                    QUERY PLAN                    
+--------------------------------------------------
+ Index Only Scan using macaddridx on macaddrtmp
+   Index Cond: (a < '02:03:04:05:06:07'::macaddr)
+(2 rows)
+
+SELECT * FROM macaddrtmp WHERE a < '02:03:04:05:06:07'::macaddr;
+         a         
+-------------------
+ 01:02:37:05:4f:36
+ 01:02:37:05:4f:36
+ 01:02:37:05:4f:36
+ 01:02:37:05:4f:36
+ 01:43:b5:79:eb:0f
+ 01:43:b5:79:eb:0f
+ 01:43:b5:79:eb:0f
+ 01:43:b5:79:eb:0f
+(8 rows)
+
diff --git a/contrib/btree_gist/expected/numeric.out b/contrib/btree_gist/expected/numeric.out
index 1ab7ae6486b..b9b67b503a2 100644
--- a/contrib/btree_gist/expected/numeric.out
+++ b/contrib/btree_gist/expected/numeric.out
@@ -186,3 +186,22 @@ SELECT count(*) FROM numerictmp WHERE a >  0 ;
    576
 (1 row)
 
+-- Test index-only scans
+SET enable_bitmapscan=off;
+EXPLAIN (COSTS OFF)
+SELECT * FROM numerictmp WHERE a BETWEEN 1 AND 300 ORDER BY a;
+                           QUERY PLAN                            
+-----------------------------------------------------------------
+ Sort
+   Sort Key: a
+   ->  Index Only Scan using numericidx on numerictmp
+         Index Cond: ((a >= 1::numeric) AND (a <= 300::numeric))
+(4 rows)
+
+SELECT * FROM numerictmp WHERE a BETWEEN 1 AND 300 ORDER BY a;
+     a      
+------------
+ 204.035430
+ 207.400532
+(2 rows)
+
diff --git a/contrib/btree_gist/expected/text.out b/contrib/btree_gist/expected/text.out
index 4905cb023bb..bb4e2e62d1d 100644
--- a/contrib/btree_gist/expected/text.out
+++ b/contrib/btree_gist/expected/text.out
@@ -71,3 +71,19 @@ SELECT count(*) FROM texttmp WHERE a  =  '2eb2c961c1cbf6 cf8d7b68cb9a2f36 7bbedb
      1
 (1 row)
 
+-- Test index-only scans
+SET enable_bitmapscan=off;
+EXPLAIN (COSTS OFF)
+SELECT * FROM texttmp WHERE a BETWEEN '31a' AND '31c';
+                        QUERY PLAN                         
+-----------------------------------------------------------
+ Index Only Scan using textidx on texttmp
+   Index Cond: ((a >= '31a'::text) AND (a <= '31c'::text))
+(2 rows)
+
+SELECT * FROM texttmp WHERE a BETWEEN '31a' AND '31c';
+  a   
+------
+ 31b0
+(1 row)
+
diff --git a/contrib/btree_gist/expected/text_1.out b/contrib/btree_gist/expected/text_1.out
index e2b9c1b6b7d..8ef1ffb2d13 100644
--- a/contrib/btree_gist/expected/text_1.out
+++ b/contrib/btree_gist/expected/text_1.out
@@ -71,3 +71,19 @@ SELECT count(*) FROM texttmp WHERE a  =  '2eb2c961c1cbf6 cf8d7b68cb9a2f36 7bbedb
      1
 (1 row)
 
+-- Test index-only scans
+SET enable_bitmapscan=off;
+EXPLAIN (COSTS OFF)
+SELECT * FROM texttmp WHERE a BETWEEN '31a' AND '31c';
+                        QUERY PLAN                         
+-----------------------------------------------------------
+ Index Only Scan using textidx on texttmp
+   Index Cond: ((a >= '31a'::text) AND (a <= '31c'::text))
+(2 rows)
+
+SELECT * FROM texttmp WHERE a BETWEEN '31a' AND '31c';
+  a   
+------
+ 31b0
+(1 row)
+
diff --git a/contrib/btree_gist/expected/time.out b/contrib/btree_gist/expected/time.out
index 1b9da4e192a..ec95ef77c57 100644
--- a/contrib/btree_gist/expected/time.out
+++ b/contrib/btree_gist/expected/time.out
@@ -77,7 +77,7 @@ SELECT a, a <-> '10:57:11' FROM timetmp ORDER BY a <-> '10:57:11' LIMIT 3;
                           QUERY PLAN                          
 --------------------------------------------------------------
  Limit
-   ->  Index Scan using timeidx on timetmp
+   ->  Index Only Scan using timeidx on timetmp
          Order By: (a <-> '10:57:11'::time without time zone)
 (3 rows)
 
diff --git a/contrib/btree_gist/expected/timestamp.out b/contrib/btree_gist/expected/timestamp.out
index cc3624f0843..0d94f2f245c 100644
--- a/contrib/btree_gist/expected/timestamp.out
+++ b/contrib/btree_gist/expected/timestamp.out
@@ -77,7 +77,7 @@ SELECT a, a <-> '2004-10-26 08:55:08' FROM timestamptmp ORDER BY a <-> '2004-10-
                                     QUERY PLAN                                     
 -----------------------------------------------------------------------------------
  Limit
-   ->  Index Scan using timestampidx on timestamptmp
+   ->  Index Only Scan using timestampidx on timestamptmp
          Order By: (a <-> 'Tue Oct 26 08:55:08 2004'::timestamp without time zone)
 (3 rows)
 
diff --git a/contrib/btree_gist/expected/timestamptz.out b/contrib/btree_gist/expected/timestamptz.out
index 88d2404c44b..75a15a42568 100644
--- a/contrib/btree_gist/expected/timestamptz.out
+++ b/contrib/btree_gist/expected/timestamptz.out
@@ -197,7 +197,7 @@ SELECT a, a <-> '2018-12-18 10:59:54 GMT+2' FROM timestamptztmp ORDER BY a <-> '
                                      QUERY PLAN                                     
 ------------------------------------------------------------------------------------
  Limit
-   ->  Index Scan using timestamptzidx on timestamptztmp
+   ->  Index Only Scan using timestamptzidx on timestamptztmp
          Order By: (a <-> 'Tue Dec 18 04:59:54 2018 PST'::timestamp with time zone)
 (3 rows)
 
diff --git a/contrib/btree_gist/expected/varbit.out b/contrib/btree_gist/expected/varbit.out
index e6765f4231f..538ace85c90 100644
--- a/contrib/btree_gist/expected/varbit.out
+++ b/contrib/btree_gist/expected/varbit.out
@@ -64,3 +64,13 @@ SELECT count(*) FROM varbittmp WHERE a >   '1110100111010'::varbit;
     50
 (1 row)
 
+-- Test index-only scans
+SET enable_bitmapscan=off;
+EXPLAIN (COSTS OFF)
+SELECT a FROM bittmp WHERE a BETWEEN '1000000' and '1000001';
+                              QUERY PLAN                               
+-----------------------------------------------------------------------
+ Index Only Scan using bitidx on bittmp
+   Index Cond: ((a >= B'1000000'::"bit") AND (a <= B'1000001'::"bit"))
+(2 rows)
+