Re: Streaming a base backup from master

Robert Haas <robertmhaas@gmail.com>

From: Robert Haas <robertmhaas@gmail.com>

To: Stephen Frost <sfrost@snowman.net>

Cc: Kevin Grittner <Kevin.Grittner@wicourts.gov>, Heikki Linnakangas <heikki.linnakangas@enterprisedb.com>, Magnus Hagander <magnus@hagander.net>, Dave Page <dpage@pgadmin.org>, PostgreSQL-development <pgsql-hackers@postgresql.org>

Date: 2010-09-03T15:41:32Z

Lists: pgsql-hackers

On Fri, Sep 3, 2010 at 11:20 AM, Stephen Frost <sfrost@snowman.net> wrote:
> Kevin,
>
> * Kevin Grittner (Kevin.Grittner@wicourts.gov) wrote:
>> While 1GB granularity would be OK, I doubt it's optimal; I think CRC
>> checks for smaller chunks might be worthwhile.  My gut feel is that
>> somewhere in the 64kB to 1MB range would probably be optimal for us,
>> although the "sweet spot" will depend on how the database is used.
>> A configurable or self-adjusting size would be cool.
>
> We have something much better, called WAL.  If people want to keep their
> backup current, they should use that after getting the base backup up
> and working.  We don't need to support this for the base backup, imv.
>
> In any case, it's certainly not something required for an initial
> implementation..

While I'm certainly not knocking WAL, it's not difficult to think of
cases where being able to incrementally update a backup saves you an
awful lot of bandwidth.

-- 
Robert Haas
EnterpriseDB: http://www.enterprisedb.com
The Enterprise Postgres Company