The following review has been posted through the commitfest application: make installcheck-world: tested, passed Implements feature: tested, passed Spec compliant: tested, passed Documentation: tested, passed
This is simple and intuitive patch. Code looks pretty clear and well documented.
I think it is good idea to decrease overhead on calling fake compressing/decomressing functions. This eliminates the need to implement the fetch function in such cases.
I also tried to disable compress and decompress functions in contrib/cube: diff --git a/contrib/cube/cube--1.2.sql b/contrib/cube/cube--1.2.sql index dea2614888..26301b71d7 100644 --- a/contrib/cube/cube--1.2.sql +++ b/contrib/cube/cube--1.2.sql @@ -370,8 +370,6 @@ CREATE OPERATOR CLASS gist_cube_ops
FUNCTION 1 g_cube_consistent (internal, cube, smallint, oid, internal), FUNCTION 2 g_cube_union (internal, internal), - FUNCTION 3 g_cube_compress (internal), - FUNCTION 4 g_cube_decompress (internal), FUNCTION 5 g_cube_penalty (internal, internal, internal), FUNCTION 6 g_cube_picksplit (internal, internal), FUNCTION 7 g_cube_same (cube, cube, internal),
And it is enables IndexOnlyScan, this is expected behaviour. + -- test explain + set enable_seqscan to 'off'; + set enable_bitmapscan to 'off'; + select count(*) from test_cube where c && '(3000,1000),(0,0)'; + count + ------- + 5 + (1 row) + + explain analyze select c from test_cube where c && '(3000,1000),(0,0)'; + QUERY PLAN + -------------------------------------------------------------------------------------------------------------------------------- + Index Only Scan using test_cube_ix on test_cube (cost=0.15..56.43 rows=16 width=32) (actual time=0.015..0.018 rows=5 loops=1) + Index Cond: (c && '(3000, 1000),(0, 0)'::cube) + Heap Fetches: 5 + Planning time: 0.038 ms + Execution time: 0.032 ms + (5 rows)
The new status of this patch is: Ready for Committer
It would be good if someone would write patch for removing useless compress/decompress methods from builtin and contrib GiST opclasses. Especially when it gives benefit in IndexOnlyScan enabling.
BTW, this change in the patch look suspicious for me.
@@ -913,7 +931,6 @@ gistproperty(Oid index_oid, int attno, ReleaseSysCache(tuple);
/* Now look up the opclass family and input datatype. */ - tuple = SearchSysCache1(CLAOID, ObjectIdGetDatum(opclass)); if (!HeapTupleIsValid(tuple)) {
We are typically evade changing formatting in fragments of codes not directly touched by the patch.
------ Alexander Korotkov Postgres Professional: http://www.postgrespro.com The Russian Postgres Company