Re: Proposal for Implenting read-only queries during wal replay (SoC 2007)

"Florian G. Pflug" <fgp@phlo.org> writes:
> I plan to submit a proposal for implementing support for
> read-only queries during wal replay as a "Google Summer of Code 2007"
> project.

You are discussing this on the wrong list.

> B) Split StartupXLOG into two steps. The first (Recovery) will process
>     only enough wal to bring the system into a consistent state,

How will you know what that is?

> C) Combine A) and B), in the simplest possible way.
>     Introduce a global R/W lock, which is taken by the Replay part
>     of B) in write mode before replaying a chunk, then released,
>     and immediatly reaquired before replaying the next chunk.

That seems certain to result in intolerable performance, for both the
queries and the replay process.
        regards, tom lane