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Re: VACUUM Performance
- From: Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>
- To: "Steve Oualline" <soualline(at)stbernard(dot)com>
- Cc: pgsql-performance(at)postgresql(dot)org, "Jiu Zheng" <Jiu(at)stbernard(dot)com>
- Subject: Re: VACUUM Performance
- Date: Sat, 21 Oct 2006 01:02:06 -0400
"Steve Oualline" <soualline(at)stbernard(dot)com> writes: > Question: I have a big table with 120,000,000 records. > Let's assume that I DELETE 4,000,000 records, VACUUM FULL, and REINDEX. > Now I have the same table, but with 240,000,000 records. > I DELETE 8,000,000 records, VACUUM FULL, and REINDEX. > Should the second operation with twice the data take twice the time as = > the first? At least. If you intend to reindex all the indexes, consider instead doing DROP INDEX(es) VACUUM FULL re-create indexes as this avoids the very large amount of effort that VACUUM FULL puts into index maintenance --- effort that's utterly wasted if you then reindex. CLUSTER and some forms of ALTER TABLE can accomplish a table rewrite with less hassle than the above, although strictly speaking they violate MVCC by discarding recently-dead tuples. regards, tom lane
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- VACUUM Performance
- From: Steve Oualline
- VACUUM Performance
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