Re: Slow query using simple equality operators

To follow up on my own email, by disabling BitmapScan in my
postgresql.conf the performance seems to be better. Is something
wrong with the query analyzer?

v=# explain select s_content,textdir from text_search where
path_id='1' AND tb_id='P2_TB00001';
QUERY PLAN
------------------------------------------------------------------------
------------------------
Index Scan using idx_search_path_id on text_search
(cost=0.00..4081857.23 rows=5083 width=36)
Index Cond: (path_id = 1)
Filter: (tb_id = 'P2_TB00001'::text)
(3 rows)

Benjamin

On Apr 23, 2007, at 3:38 PM, Benjamin Arai wrote:

> Can anybody explain to me why this query is executing so slow?
>
> =# explain select s_content,textdir from text_search where
> path_id='1' AND tb_id='P2_TB00001';
> QUERY PLAN
> ----------------------------------------------------------------------
> ---------------------------
> Bitmap Heap Scan on text_search (cost=39861.94..59743.55 rows=5083
> width=36)
> Recheck Cond: ((path_id = 1) AND (tb_id = 'P2_TB00001'::text))
> -> BitmapAnd (cost=39861.94..39861.94 rows=5083 width=0)
> -> Bitmap Index Scan on idx_search_path_id
> (cost=0.00..16546.09 rows=1016571 width=0)
> Index Cond: (path_id = 1)
> -> Bitmap Index Scan on idx_search_tb_id
> (cost=0.00..23315.60 rows=1016571 width=0)
> Index Cond: (tb_id = 'P2_TB00001'::text)
> (7 rows)
>
> Thanks in advance!
>
> Benjamin
>
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