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Message-ID: <20041124192330.5327.qmail@web52804.mail.yahoo.com>
Date: Wed, 24 Nov 2004 11:23:30 -0800 (PST)
From: Mark Dilger <markdilger@yahoo.com>
Subject: Explicitly rolling back transaction from within a C-Language function
To: pgsql-sql@postgresql.org
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii

Hello,

I have a transactional system built on top of
BerkeleyDB which I would like to call from within
Postgres through a C-Language function.  The behavior
of the function will be read-only.  Even so, the
BerkeleyDB-based system's transaction will sometimes
fail.  What I would like to do is propogate that
transactional failure into the Postgres transaction
that called the C-Language function.  Is this
possible?

To clarify what I think I want:  I would like the
C-Language function to return an error condition to
Postgres that will cause the current Postgres
transaction to abort.  I do not know how to do this.

I am not particularly worried about needing to
rollback the BerkeleyDB transaction when the Postgres
transaction fails, because the BerkeleyDB transaction
was read-only anyway, and there are no updates to roll
back.  However, I might want to do this in the future
so information on this subject is also welcome.

Thank you for any help,

mark


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