Re: Only first XLogRecData is visible to rm_desc with WAL_DEBUG

On Tue, Mar 25, 2014 at 12:30 AM, Heikki Linnakangas
<hlinnakangas(at)vmware(dot)com> wrote:
>>> I've found WAL_DEBUG quite useful in the past, when working on
>>> scalability, and have indeed wished for it to be
>>> compiled-in-by-default.
>>>
>>> I don't know whether I'm the only one, though.
>>
>> You are not. I would rather have it fixed than removed, if possible. I
>> don't really care too much about getting a performance hit to palloc the
>> records, really; being able to actually read what's happening is much
>> more useful.
>
> I find it useful too, but I think pg_xlogdump can serve the same purpose.
>
> One thing missing from pg_xlogdump is the capability to keep tracking the
> inserted WAL, instead of dumping to the end of WAL and stopping there. If we
> add an option to pg_xlogdump to poll the WAL instead of bailing out at an
> error, I think it's a good replacement.

Well, one nice thing about wal_debug is that the WAL is at that point
still associated with the session that generated it. But I grant
that's not a huge issue. How much work are we talking about to fix
this, though?

--
Robert Haas
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