From: "Hiroshi Inoue" <Inoue@tpf.co.jp>
To: "Tom Lane" <tgl@sss.pgh.pa.us>
Cc: "Hiroki Kataoka" <kataoka@interwiz.koganei.tokyo.jp>,
	<pgsql-interfaces@postgresql.org>, <pgsql-odbc@postgresql.org>,
	"Steve Wranovsky" <stevew@merge.com>
Subject: RE: 7.1 beta 3 Linux ODBC BEGIN Behaviour 
Date: Sun, 11 Feb 2001 06:37:02 +0900
Message-ID: <EKEJJICOHDIEMGPNIFIJCEBDDJAA.Inoue@tpf.co.jp>
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> -----Original Message-----
> From: Tom Lane
> 
> It'd be nice if ODBC could distinguish SELECT FOR UPDATE from plain
> SELECT, but in practice it cannot reliably do so.  Doubtless we could
> extend ODBC to look for "FOR UPDATE" in the text of the query, but
> that will only catch simple situations.  Consider these possibilities:
> 
> * A view or rule invoked by the query uses FOR UPDATE.  (Pre-7.1, we
> didn't support FOR UPDATE in views ... but we do now.)
> 
> * A function invoked by the query does SELECT FOR UPDATE internally.
> 
> For that matter, it's quite possible for a function invoked by a SELECT
> to do INSERT/UPDATE/DELETE internally.  Therefore, it's impossible for
> the ODBC driver to reliably distinguish a pure SELECT from a SELECT that
> causes locking or even data updates.
> 
> Given these considerations, I think it's a mistake for ODBC to treat
> SELECT differently from other queries for the purpose of setting
> transaction boundaries.
>

OK, agreed. 
However simply putting back the behabior make it impossible to call
VACUUM in psqlodbc autocommit off mode.

My idea is as follows.
 [In autocommit off mode]
 1) All statements except STMT_TYPE_OTHER issue
     "BEGIN" if a trasaction isn't in progress.
 2) STMT_TYPE_OTHER statements automatically issue
    "COMMIT" if a transaction is progress.

Comments ?

Regards,
Hiroshi Inoue