On Thu, Apr 29, 2010 at 1:03 PM, Tom Lane <tgl@sss.pgh.pa.us> wrote:
>>> That said, I'ld probalby be happy with PG 9 having a "default" config
>>> of:
>>> wal_mode = hot_standby
>>> recovery_connections = on
>
>> That would be a bad idea - there's a significant performance penalty
>> from setting wal_level to anything other than minimal (just as there
>> is for turning on archive_mode in 8.4).
>
> There is not only a performance penalty, but a reliability penalty.
> Enabling these switches turns on a whole lot of code that, with all
> due respect to those who have worked on it, is absolutely positively
> guaranteed to be full of bugs. Not all of which are going to be flushed
> out during beta. If we ship 9.0 with these things on by default, it
> will result in an immediate reliability downgrade for installations that
> are simply doing what they did before and not even interested in HS/SR.
This is a pretty good argument, and Heikki's argument just upthread
that a mismatched max_connections setting could bollix things is an
even better one. So I'm now changing my mind and thinking this should
be off by default, also.
...Robert
