Re: Improve compression speeds in pg_lzcompress.c
Tom Lane <tgl@sss.pgh.pa.us>
From: Tom Lane <tgl@sss.pgh.pa.us>
To: Robert Haas <robertmhaas@gmail.com>
Cc: Takeshi Yamamuro <yamamuro.takeshi@lab.ntt.co.jp>, pgsql-hackers@postgresql.org
Date: 2013-01-07T21:19:36Z
Lists: pgsql-hackers
Robert Haas <robertmhaas@gmail.com> writes: > On Mon, Jan 7, 2013 at 11:16 AM, Tom Lane <tgl@sss.pgh.pa.us> wrote: >> Why would that be a good tradeoff to make? Larger stored values require >> more I/O, which is likely to swamp any CPU savings in the compression >> step. Not to mention that a value once written may be read many times, >> so the extra I/O cost could be multiplied many times over later on. > I agree with this analysis, but I note that the test results show it > actually improving things along both parameters. Hm ... one of us is reading those results backwards, then. regards, tom lane