Re: Libpq support for precision and scale - Mailing list pgsql-hackers

From Fernando Nasser
Subject Re: Libpq support for precision and scale
Date
Msg-id 3C881BB1.78D198B2@redhat.com
Whole thread Raw
In response to Re: Libpq support for precision and scale  (Bruce Momjian <pgman@candle.pha.pa.us>)
List pgsql-hackers
Tom Lane wrote:
> 
> Fernando Nasser <fnasser@redhat.com> writes:
> > We have agreed to add another call to set a flag for including the
> > metadata on the PQexec call (which would make it work like the
> > PQexecIncludeMetadata described above).  It will be in the REPOST patch.
> 
> That works for me.  Among other things, it solves the problem where the
> code that wants the metadata is a layer or two above the place that's
> actually issuing PQexec.  Setting a persistent option in the PGconn
> object gets around the difficulty that the caller of PQexec may not know
> metadata will be wanted later.
> 
> > Question: should it affect only the next PQexec(), or should we require
> > the user to reset it?
> 
> It should be persistent till reset, see above.
> 

Agreed.


> > An even worse problem is that
> > it'll fail entirely with a multi-query query string.
> 
> I'm still quite unhappy about this; it more or less destroys the layer
> independence mentioned above.  Please think harder.  Perhaps it could
> be set up so that metadata is only collected for the last result of a
> query string, after you determine that there are no more results?
> Which is still not great, but better than failing outright with
> multi-query strings.
> 

I will look into doing like you suggest.

-- 
Fernando Nasser
Red Hat Canada Ltd.                     E-Mail:  fnasser@redhat.com
2323 Yonge Street, Suite #300
Toronto, Ontario   M4P 2C9


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