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Re: Use of index for 50% column restriction - Mailing list pgsql-hackers

From Jim Nasby
Subject Re: Use of index for 50% column restriction
Date
Msg-id 8d7c9f3a-93d3-a1e0-164b-d2f32a5a5f20@BlueTreble.com
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In response to Re: Use of index for 50% column restriction  (Bruce Momjian <bruce@momjian.us>)
Responses Re: Use of index for 50% column restriction  (Bruce Momjian <bruce@momjian.us>)
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On 6/8/16 4:36 PM, Bruce Momjian wrote:
> Just a follow-up, but even with a randomized correlation order, it seems
> 25% restrictivity generates a Bitmap Index Scan:

AFAIK we do the bitmap heap scan in heap order, thereby eliminating the 
effect of correlation?
-- 
Jim Nasby, Data Architect, Blue Treble Consulting, Austin TX
Experts in Analytics, Data Architecture and PostgreSQL
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