Analysis: ======== While debugging bitmap heap scan (BitmapHeapNext function) found that first we perform the underlying index scan and then iterate over bitmap. Now while iterating, we execute ExecQual only if tbmres->recheck is true. And for the query tbmres->recheck is false.
But from the query it seems that we should execute ExecQual as we having "bitmpaqual" on the BitmapHeap node (Not quite sure). And when I manually did recheck = ture, query working fine and as expected. Regards. Rushabh www.EnterpriseDB.com On Wed, Nov 19, 2008 at 4:26 PM, Rushabh Lathia <[EMAIL PROTECTED]>wrote: > Simple select give wrong result when it uses the Bitmap Heap Scan path. > > > postgres=# CREATE OR REPLACE FUNCTION my_exec_im_test_func(i integer) > RETURNS integer AS $$ > BEGIN > RETURN i + 1; > END; > $$ LANGUAGE plpgsql; > CREATE FUNCTION > > postgres=# set enable_seqscan=off; > SET > postgres=# set enable_indexscan=off; > SET > postgres=# select proname from pg_proc where proname like 'my_pro1'; > proname > ---------------------- > my_exec_im_test_proc > (1 row) > > postgres=# explain select proname from pg_proc where proname like > 'my_pro1'; > QUERY > PLAN > > > -------------------------------------------------------------------------------- > ------------- > Bitmap Heap Scan on pg_proc (cost=4.26..8.27 rows=1 width=64) > Recheck Cond: (proname ~~ 'my_pro1'::text) > -> Bitmap Index Scan on pg_proc_proname_args_nsp_index > (cost=0.00..4.26 row > s=1 width=0) > Index Cond: ((proname >= 'my'::name) AND (proname < 'mz'::name)) > (4 rows) > > > > > -- > Rushabh Lathia > > www.EnterpriseDB.com -- Rushabh Lathia
