Re: Creation of temporary tables on read-only standby servers

On Mon, Oct 18, 2010 at 3:26 PM, Tom Lane <tgl@sss.pgh.pa.us> wrote:
> Andres Freund <andres@anarazel.de> writes:
>> On Monday 18 October 2010 20:06:01 Tom Lane wrote:
>>> Not unless you have some credible concept for how it might ever be
>>> implemented.  You can't create temp tables because you can't modify
>>> system catalogs, and if you did somehow create them you couldn't put
>>> anything in them because you can't generate XIDs on a slave ... much
>>> less commit them.  We have talked about ways that temp tables might be
>>> created without touching the "real" system catalogs, but the XID issue
>>> seems a complete showstopper.
>
>> Hm. Wouldnt it be possible to use virtual xids for that purpose? They are
>> never seen outside of that session anyway...
>
> Well, maybe, but then you need infrastructure to track whether VXIDs
> committed or aborted.

Seems like this would wreak havoc with the HeapTupleSatisfies* functions.

--
Robert Haas
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