Re: Why adding BEFORE TRIGGER affect client CPU?

Adrian Klaver <adrian(dot)klaver(at)aklaver(dot)com> writes:
> On 1/18/19 10:23 AM, George Woodring wrote:
>> We recently changed the process to do a BEFORE TRIGGER to do the
>> calculation between OLD and NEW instead of the separate function with
>> the SELECT.

> So what was the exact change?

>> After doing this, CPU on our two client servers went crazy.  CPU on the
>> database servers look unchanged.  Rolling back this change fixed our
>> client CPU issue.

> What is the client server and what is it doing?

Indeed. There's no direct way that messing with a trigger would have
caused extra CPU on the client side. I speculate that the trigger
caused the data to look different in a way that your client app wasn't
expecting, causing it to do something funny --- maybe loop trying to
find a matching record, or something like that. Or maybe removing the
step that did the calculation client-side had side effects you weren't
expecting --- what uses that value client-side, exactly?

regards, tom lane