Re: pgsql: Avoid tricky race condition recording XLOG_HINT

On 2013-04-08 10:47:50 -0400, Tom Lane wrote:
> Simon Riggs <simon(at)2ndQuadrant(dot)com> writes:
> > On 8 April 2013 15:29, Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> wrote:
> >> Just for the record, the right way to handle that kind of change is to
> >> change XLOG_PAGE_MAGIC, not catversion. A database's catalog version
> >> might not be available to code that is inspecting WAL files and would
> >> like to know what format it should expect.
>
> > I was so happy Andres had remembered to bump the catversion like I often
> > do, it didn't occur to me it was the wrong one. My bad, sorry.

Sorry for that.

> No problem. XLOG_PAGE_MAGIC is already different from what it was in
> 9.2, so it's mostly academic whether or not we bump it again during
> the devel cycle.

I just didn't want anybodys devel instance crashing because it accessed
record data that previously didn't exist. XLOG_PAGE_MAGIC space looks so
much more sparse than catversion's ;)

Greetings,

Andres Freund

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