RE: Do triggers cause a context switch between SQL & PL/SQL

From: Jacques Kilchoer <Jacques.Kilchoer_at_quest.com>
Date: Wed, 02 Apr 2003 08:58:39 -0800
Message-ID: <F001.005782D4.20030402085839@fatcity.com>

Well yes. I was pointing out a second way to write the query that avoided selecting from dual. But the time it takes to run the query is the same in both examples.

-----Original Message-----

I am not sure ... so far as I know "select count(*) from some_table" without any further group by has always resulted in one row ...

-----Original Message-----

Your query with the exists would be the same as doing this, right? select count(*)
  into numrows
from ApplicationFormCriteria
where ApplicationFormCriteria.applicationFormId = :old.applicationFormId

      and rownum = 1 ;

-----Original Message-----

A context switch is order because a trigger is a pl/sql object ... if you can change the trigger ... instead of count(*) try using exists assuming you have a usable index ...
select count(*)
  into numrows
from dual
where exists ( select 1

                from ApplicationFormCriteria 
               where ApplicationFormCriteria.applicationFormId =

:old.applicationFormId);

...

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-- 
Author: Jacques Kilchoer
  INET: Jacques.Kilchoer_at_quest.com

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Received on Wed Apr 02 2003 - 10:58:39 CST