To: "Merlin Moncure" <merlin.moncure@rcsonline.com>
Cc: pgsql-hackers@postgresql.org, "Gavin Sherry" <swm@linuxworld.com.au>,
	"Neil Conway" <neilc@samurai.com>
Subject: Re: Where are we on stored procedures? 
In-reply-to: <6EE64EF3AB31D5448D0007DD34EEB3412A7632@Herge.rcsinc.local> 
References: <6EE64EF3AB31D5448D0007DD34EEB3412A7632@Herge.rcsinc.local>
Comments: In-reply-to "Merlin Moncure" <merlin.moncure@rcsonline.com>
	message dated "Fri, 25 Feb 2005 08:07:53 -0500"
Date: Fri, 25 Feb 2005 10:23:16 -0500
Message-ID: <5155.1109344996@sss.pgh.pa.us>
From: Tom Lane <tgl@sss.pgh.pa.us>

"Merlin Moncure" <merlin.moncure@rcsonline.com> writes:
>> 1. Executing outside the database engine, and therefore being able to
>> start/commit transactions.  (This is *fundamentally* different from our
>> current concept of functions, and I think that any implementation that
>> tries to gloss over the difference will be doomed to failure.)

> Back in the early days of nested transactions, you could begin/commit
> while within a transaction...they could be pushed and popped off of a
> stack.

Those weren't actual transaction starts or commits though; they were
(in our current terminology) savepoints.  People want *real* commits
in stored procedures, not fakes.  For instance consider an SP that
wants to issue a series of VACUUM commands --- if there's a hidden
transaction block around the SP, this must fail.  Locking considerations
may force use of real commits and real rollbacks, too.  You can't
release a lock by committing a subtransaction.

			regards, tom lane