> That is bizarre. Does EXPLAIN show any difference?
Uh oh.
esp=# reindex table data1.parts_order_line_file;
REINDEX
esp=# explain analyze select 1::int4, * from data1.po_line_file
esp-# where pol_po_no = '00000002' and
esp-# (pol_po_no = '00000002' and pol_po_rel_no = 0) and
esp-# (pol_po_no = '00000002' and pol_po_rel_no = 0 and
pol_item_no = '1570')
esp-# limit 1 ;
QUER
Y PLAN
------------------------------------------------------------------------
----------------------------
------------------------------------------------------------------------
----------------------------
--Limit (cost=0.00..5.76 rows=1 width=313) (actual time=0.000..0.000
rows=0 loops=1) -> Index Scan using po_line_file_pkey on po_line_file
(cost=0.00..5.76 rows=1 width=313) (actua
l time=0.000..0.000 rows=0 loops=1) Index Cond: ((pol_po_no = '00000002'::bpchar) AND (pol_po_no =
'00000002'::bpchar) AND (pol
_po_no = '00000002'::bpchar) AND ((pol_po_rel_no)::smallint = 0) AND
((pol_po_rel_no)::smallint = 0)
) Filter: ((pol_item_no)::text = '1570'::text)Total runtime: 0.000 ms
(5 rows)