Re: Feedback on getting rid of VACUUM FULL - Mailing list pgsql-hackers

From Josh Berkus
Subject Re: Feedback on getting rid of VACUUM FULL
Date
Msg-id 4AB13995.6040901@agliodbs.com
Whole thread Raw
In response to Re: Feedback on getting rid of VACUUM FULL  (Hannu Krosing <hannu@2ndQuadrant.com>)
List pgsql-hackers
Hannu,

> If it is a sequence of
> 
> 1. ordinary VACUUM (it can't run out of FSM anymore, no?)
> 2. a process moving live tuples from end (using reverse seqscan) to free
> space found scanning in first-to-last direction, either one tuple at a
> time or one page at a time, until the two scans meet
> 3. another ordinary VACUUM to actually reclaim the free space
> 
> 4. repeat a few times so that tuples at the end of relation (for
> whatever reason) added while doing 1-3 are also moved towards beginning

Sounds good, you want to code it for 8.5?

I could actually see two tools, one VACUUM FULL CONCURRENTLY and one
VACUUM REWRITE.  The first would be "in place" and the second would be
"fast".  Both should work better with HS than current VF does.

-- 
Josh Berkus
PostgreSQL Experts Inc.
www.pgexperts.com


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