[Pgpool-general] Multi-statement queries

[Glyn Astill]

Yeah I'm with Daniel on this one, Tatsuo?

--- On Tue, 9/3/10, Daniel.Crespo at l-3com.com <Daniel.Crespo at l-3com.com> wrote:

> From: Daniel.Crespo at l-3com.com <Daniel.Crespo at l-3com.com>
> Subject: Re: [Pgpool-general] Multi-statement queries
> To: "Matthias Tief" <matthias at itso-berlin.de>, pgpool-general at pgfoundry.org
> Date: Tuesday, 9 March, 2010, 14:50
> My experience is also that
> multi-statement queries ("statement1; statement2; ...;
> statementN;") work in pgpool-II, so now I'm confused with
> "pgpool-II cannot process multi-statement query". Also, why
> wouldn't it work if PostgreSQL itself does? I think the idea
> is pgpool-II to work transparently as connecting directly to
> PostgreSQL.
> 
> Daniel
> 
> > -----Original Message-----
> > From: pgpool-general-bounces at pgfoundry.org
> [mailto:pgpool-general-
> > bounces at pgfoundry.org]
> On Behalf Of Matthias Tief
> > Sent: Tuesday, March 09, 2010 4:11 AM
> > To: pgpool-general at pgfoundry.org
> > Subject: Re: [Pgpool-general] Multi-statement queries
> > 
> > Thank you for your rapid answer.
> > 
> > But for me it is still not clear. What you describe
> seems to be a
> > collection of statements transmitted as a single
> transaction. But this
> > is done very well by pgpool-II in my tests. I am wrong
> with that?
> > 
> > So than my question is: What is the difference between
> "multi-statement
> > queries" and a single transaction of multiple
> statements?
> > 
> > As I understand pgadmin implicitly wrapps a
> BEGIN/COMMIT block around
> > all statements, that it becomes a single transaction.
> > 
> > Looking forward to your answer.
> > 
> > Matthias
> > 
> > Guillaume Lelarge schrieb:
> > > Le 05/03/2010 09:45, Matthias Tief a écrit :
> > >> Hallo,
> > >>
> > >> we are planning to use pgpool-II as
> replication solution for our
> > >> PostgeSQL application. Currently we evaluate,
> whether the
> > restriction of
> > >> pgpool-II affect our application. In the
> documentation you say:
> > >> "pgpool-II cannot process multi-statement
> query." What do you
> > exactly
> > >> mean with "multi-statement queries". As I
> found out you don't mean
> > >> transactions that contain multiple statments,
> like BEGIN - COMMIT
> > >> blocks. These blocks are "committed" or in
> case of a failure are
> > "rolled
> > >> back" correctly. I would appreciate if you
> could give me an example
> > of
> > >> multi-statement queries.
> > >>
> > >
> > > "statement1; statement2; statement3;" in a single
> trip to the
> > backend.
> > >
> > > For example:
> > >
> > > "INSERT INTO t1 VALUES (1); INSERT INTO t1 VALUES
> (2); INSERT INTO t1
> > > VALUES (3);"
> > >
> > > is a multi-statement query, whereas
> > >
> > > "INSERT INTO t1 VALUES (1);"
> > > then
> > > "INSERT INTO t1 VALUES (2);"
> > > then
> > > "INSERT INTO t1 VALUES (3);"
> > >
> > > are three one-statement queries.
> > >
> > > pgAdmin uses this quite a lot ("SET
> client_encoding TO utf8; SELECT *
> > > FROM...").
> > >
> > >
> > 
> > --
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> > Mohrenstr. 63-64; D-10117 Berlin
> > Tel.: +49 (030) 220791-30
> > Fax: +49 (030) 220791-55
> > Email: matthias.tief at itso-berlin.de
> > Internet: www.itso.de
> > Amtsgericht Berlin Charlottenburg HRB 21013
> > 
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