Re: Partial Index Too Literal?

use this explain analyze select * from result where active = 't'; --- On Thu, 6/26/08, Phillip Mills <pmills@systemcore.ca> wrote: From: Phillip Mills <pmills@systemcore.ca> Subject: [GENERAL] Partial Index Too Literal? To: pgsql-general@postgresql.org Date: Thursday, June 26, 2008, 7:24 PM Under somewhat unusual circumstances, rows in one of our tables have an 'active' flag with a true value.  We check for these relatively often since they represent cases that need special handling.  We've found through testing that having a partial index on that field works well.  What seems odd to me, however, is that the index gets used only if the query is a textual match for how the index was specified. That is, using an index defined as 'where active = true': dev=# explain analyze select * from result where active = true;                                                              QUERY PLAN -------------------------------------------------------------------------------------------------------------------------------------  Bitmap Heap Scan on result (cost=5.31..472.34 rows=4206 width=1126) (actual time=7.868..7.868 rows=0 loops=1)    Filter: active    ->  Bitmap Index Scan on result_active_idx  (cost=0.00..4.26 rows=2103 width=0) (actual time=4.138..4.138 rows=16625 loops=1)          Index Cond: (active = true)  Total runtime: 7.918 ms (5 rows) dev=# explain analyze select * from result where active is true;                                                   QUERY PLAN --------------------------------------------------------------------------------------------------------------  Seq Scan on result (cost=0.00..537.26 rows=4263 width=1126) (actual time=55.631..55.631 rows=0 loops=1)    Filter: (active IS TRUE)  Total runtime: 55.668 ms (3 rows) This is version 8.2.6.  Is there something I'm missing that could make these queries ever produce different results?