Evaluate arbitrary expression on tuple inside trigger function?

From: Tom Dunstan <pgsql(at)tomd(dot)cc>
To: pgsql-hackers(at)postgresql(dot)org
Subject: Evaluate arbitrary expression on tuple inside trigger function?
Date: 2013-07-29 03:29:27
Message-ID: CAPPfruzxVEQ8V4fay=4=1dOPyRiB7-REN2wHjK4ZK965bWH67A@mail.gmail.com
Views: Raw Message | Whole Thread | Download mbox | Resend email
Thread:
Lists: pgsql-hackers

Hi all

I'm trying to hack a trigger function to evaluate an expression on the
tuple that the trigger has been fired for, kinda like a check
constraint. I looked at ExecRelCheck in execMain.c which does
more-or-less what I want to do, and I have the parsed node tree all
ready to go. The problem that I'm facing is that ExecRelCheck uses a
passed in EState to set up the executor in the right mode, and with
the right memory context, but the EState doesn't get passed in to the
trigger function, and I can't see anything obvious hanging off the
TriggerData that does get passed in that would give me access to it.

Can anyone either point me to where I might be able to get a handle on
the current EState, or otherwise recommend a way forward?

Thanks

Tom

Responses

Browse pgsql-hackers by date

  From Date Subject
Next Message Tom Lane 2013-07-29 05:05:42 Bison 3.0 updates
Previous Message Stephen Frost 2013-07-29 03:13:34 Re: [COMMITTERS] pgsql: Add GET DIAGNOSTICS ... PG_CONTEXT in PL/PgSQL