many 'OR' in WHERE-condition

Hello,

a friend of mine has got a problem:

in a SELECT with a condition 'WHERE foo IN (1,2,3,4,...)' with a large
list within. The optimizer choose a rewrite to many OR's and a bitmap
index scan on the index, no problem, fast.

But if the list increase the planner choose an seq-scan. The amount of
values in the list is about 200 and the table has about 250.000 rows.


How can we avoid the seq-scan?


Andreas, thx in advance.
-- 
Andreas Kretschmer
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