Re: 8.5 TODO: any info on "Create dump tool for write-ahead logs..." in PITR section (1.4)?

shakahshakah(at)gmail(dot)com wrote:
> Can anyone elaborate (or point me to some additional info) on the 8.5
> TODO item in the "Point-In-Time Recover (PITR) section (1.4)":
> Create dump tool for write-ahead logs for use in determining
> transaction id for point-in-time recovery
> This is useful for checking PITR recovery.
>
> I poked around a bit and found some code that "walks" the WAL logs (in
> src/backend/access/transam/xlog.c, I think) and I could probably
> figure out how to display a WAL log file contents, but I'm hoping
> someone can provide some context as to what issue this TODO item is
> trying to address (i.e., what output would be useful).

That TODO item is a lot less important after we have Hot Standby. It
contains functions that allow you to pause and continue WAL replay, and
step through the WAL one transaction at a time. It won't let you go
backwards, though, so it won't completely replace a tool like xlogdump,
which you can use to look into the WAL before applying it.

--
Heikki Linnakangas
EnterpriseDB http://www.enterprisedb.com