On 3/9/2012 9:47 AM, Merlin Moncure wrote:
On Thu, Mar 8, 2012 at 2:01 PM, Andy Colson<andy@xxxxxxxxxxxxxxx> wrote:
I know toast compresses, but I believe its only one row. page level would
compress better because there is more data, and it would also decrease the
amount of IO, so it might speed up disk access.
er, but when data is toasted it's spanning pages. page level
compression is a super complicated problem.
something that is maybe more attainable on the compression side of
things is a userland api for compression -- like pgcrypto is for
encryption. even if it didn't make it into core, it could live on
reasonably as a pgfoundry project.
merlin
Agreed its probably too difficult for a GSoC project. But userland api
would still be row level, which, in my opinion is useless. Consider
rows from my apache log that I'm dumping to database:
date, url, status
2012-3-9 10:15:00, '/index.php?id=4', 202
2012-3-9 10:15:01, '/index.php?id=5', 202
2012-3-9 10:15:02, '/index.php?id=6', 202
That wont compress at all on a row level. But it'll compress 99% on a
"larger" (page/multirow/whatever/?) level.
-Andy
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