Re: Compression of full-page-writes

On 2013-10-22 12:52:09 +0900, Fujii Masao wrote:
> So, our consensus is to introduce the hooks for FPW compression so that
> users can freely select their own best compression algorithm?

No, I don't think that's concensus yet. If you want to make it
configurable on that level you need to have:
1) compression format signature on fpws
2) mapping between identifiers for compression formats and the libraries implementing them.

Otherwise you can only change the configuration at initdb time...

> Also, probably we need to implement at least one compression contrib module
> using that hook, maybe it's based on pglz or snappy.

From my tests for toast compression I'd suggest starting with lz4.

I'd suggest starting by publishing test results with a more modern
compression formats, but without hacks like increasing padding.

Greetings,

Andres Freund

-- Andres Freund                       http://www.2ndQuadrant.com/PostgreSQL Development, 24x7 Support, Training &
Services