From: Tom Lane <tgl@sss.pgh.pa.us>
To: Merlin Moncure <merlin.moncure@rcsonline.com>
Cc: pgsql-performance@postgresql.org
Subject: Re: improvise callbacks in plpgsql
Date: Tue, 01 Nov 2005 16:29:22 -0500
Message-ID: <28343.1130880562@sss.pgh.pa.us> (raw)
In-Reply-To: <6EE64EF3AB31D5448D0007DD34EEB3417DD754@Herge.rcsinc.local>
References: <6EE64EF3AB31D5448D0007DD34EEB3417DD754@Herge.rcsinc.local>
"Merlin Moncure" <merlin.moncure@rcsonline.com> writes:
> A simplified idealized version of what I would like to do is
> begin
> select (callback_routine)(record_type)
> end;
> from within a plpgsql function. I am borrowing the C syntax for a
> function pointer here.
Well, there's no function pointer type in SQL :-(. I don't see any way
to do what you want in pure plpgsql. If you're willing to implement an
auxiliary C function you could probably make it go:
create function callit(oid, record) returns void ...
where the OID has to be the OID of a function taking a record-type
argument. The regprocedure pseudotype would allow you not to need
to write any numeric OIDs in your code:
select callit('myfunc(record)'::regprocedure, recordvar);
The body of callit() need be little more than OidFunctionCall1()
plus whatever error checking and security checking you want to
include.
regards, tom lane
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To: pgsql-performance@postgresql.org
Cc: tgl@sss.pgh.pa.us, merlin.moncure@rcsonline.com
Subject: Re: improvise callbacks in plpgsql
In-Reply-To: <28343.1130880562@sss.pgh.pa.us>
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