Re: Improve compression speeds in pg_lzcompress.c
Robert Haas <robertmhaas@gmail.com>
From: Robert Haas <robertmhaas@gmail.com>
To: Tom Lane <tgl@sss.pgh.pa.us>
Cc: Takeshi Yamamuro <yamamuro.takeshi@lab.ntt.co.jp>, pgsql-hackers@postgresql.org
Date: 2013-01-07T21:07:51Z
Lists: pgsql-hackers
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. I'm not sure how general that result is. -- Robert Haas EnterpriseDB: http://www.enterprisedb.com The Enterprise PostgreSQL Company