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Re: Slow query performance
Posted by: Aleksey Kishkin
Date: October 13, 2004 10:48PM

Matt,

count(*) (you use in explain) and count(BLOCKGROUP_ID) are pretty different.
count(*) - counts all records.
count(BLOCKGROUP_ID) - counts all records with not null BLOCKGROUP_ID
so, 'explains' for them can differ.

could you please to provide explain for
SELECT COUNT(BLOCKGROUP_ID) FROM BLOCKGROUP_DEMOGRAPHIC;
?

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