Re: [GENERAL] 7.4Beta - Mailing list pgsql-hackers

From Tom Lane
Subject Re: [GENERAL] 7.4Beta
Date
Msg-id 12535.1060948630@sss.pgh.pa.us
Whole thread Raw
In response to Re: [GENERAL] 7.4Beta  (Stephan Szabo <sszabo@megazone.bigpanda.com>)
Responses Re: [GENERAL] 7.4Beta
Re: [GENERAL] 7.4Beta
List pgsql-hackers
Stephan Szabo <sszabo@megazone.bigpanda.com> writes:
> select * from fk where not exists(select * from pk where pk.key=fk.key)
>  and key is not null;
> (doing seq scan/subplan doing index scan - which is probably close to the
> current system)

Actually, even that would probably be noticeably better than the current
system.  I haven't profiled it (someone should) but I suspect that
executor startup/shutdown time is a huge hit.  Even though the trigger
is caching a plan, it has to instantiate that plan for each referencing
tuple --- and the executor is not designed for quick startup/shutdown.

(Of course, this would become less relevant if the triggers got
rewritten to not go through SPI ...)
        regards, tom lane


pgsql-hackers by date:

Previous
From: Tom Lane
Date:
Subject: ADD FOREIGN KEY (was Re: [GENERAL] 7.4Beta)
Next
From: Tom Lane
Date:
Subject: Re: New function: epoch_to_timestamp...