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Home -> Community -> Mailing Lists -> Oracle-L -> Re: Do triggers cause a context switch between SQL & PL/SQL
I did some bulk load testing with triggers on v8.1.7.4 a few months ago. All the trigger(s) had for code was a "NULL;" statement. The first trigger increased the time 100% in the insert (ie: a load that took 1 minute increased to 2 minutes with the trigger). Each additional trigger after the first cost an additional 25%.
So I would read that as a 75% cost/increase to do the SQL to PLSQL switch.
DEEDSD_at_Nationwide
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root_at_fatcity.com Subject: Re: Do triggers cause a context switch between SQL & PL/SQL
04/01/03 12:43 PM
Please respond to
ORACLE-L
I thought as much, from what I've heard and read. Does anyone know if there's a way to figure out how much overhead the switches generate? I'm guessing they would show up in trace files in the 'other CPU' category.
Jared.Still_at_radisys.com
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04/01/03 01:19 PM Subject:
Re: Do
Please respond to triggers cause a context
switch between SQL & PL/SQL
ORACLE-L
Since you the action switches from SQL to PL/SQL to enforce the trigger, it sounds like a context switch to me.
FYI: This can be improved somewhat by adding "and rownum < 2 " into the WHERE clauses of these. There will be noticable improvement when there are many child rows.
Jared
DEEDSD_at_Nationwide.com
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04/01/2003 09:48 AM
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To: Multiple recipients of list ORACLE-L <ORACLE-L_at_fatcity.com>
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Subject: Do triggers cause a context switch between SQL &
PL/SQL
Question:
If some idiot decides to circumvent Oracle's referential integrity and re-implement it by using triggers (insert, update, delete) that checks the foreign (parent/child) key fields in other tables like this,
declare numrows INTEGER;
begin
end;
would it cause context switching between the SQL & PL/SQL engines?
Yes, some genius did this in one of our databases. Two hundred third/fourth normal form tables enforced by 800 triggers... I have him registered to be stoned in public.
-- Please see the official ORACLE-L FAQ: http://www.orafaq.net -- Author: INET: DEEDSD_at_Nationwide.com Fat City Network Services -- 858-538-5051 http://www.fatcity.com San Diego, California -- Mailing list and web hosting services --------------------------------------------------------------------- To REMOVE yourself from this mailing list, send an E-Mail message to: ListGuru_at_fatcity.com (note EXACT spelling of 'ListGuru') and in the message BODY, include a line containing: UNSUB ORACLE-L (or the name of mailing list you want to be removed from). You may also send the HELP command for other information (like subscribing). -- Please see the official ORACLE-L FAQ: http://www.orafaq.net -- Author: INET: Jared.Still_at_radisys.com Fat City Network Services -- 858-538-5051 http://www.fatcity.com San Diego, California -- Mailing list and web hosting services --------------------------------------------------------------------- To REMOVE yourself from this mailing list, send an E-Mail message to: ListGuru_at_fatcity.com (note EXACT spelling of 'ListGuru') and in the message BODY, include a line containing: UNSUB ORACLE-L (or the name of mailing list you want to be removed from). You may also send the HELP command for other information (like subscribing). -- Please see the official ORACLE-L FAQ: http://www.orafaq.net -- Author: INET: DEEDSD_at_Nationwide.com Fat City Network Services -- 858-538-5051 http://www.fatcity.com San Diego, California -- Mailing list and web hosting services --------------------------------------------------------------------- To REMOVE yourself from this mailing list, send an E-Mail message to: ListGuru_at_fatcity.com (note EXACT spelling of 'ListGuru') and in the message BODY, include a line containing: UNSUB ORACLE-L (or the name of mailing list you want to be removed from). You may also send the HELP command for other information (like subscribing). -- Please see the official ORACLE-L FAQ: http://www.orafaq.net -- Author: INET: Brian_P_MacLean_at_eFunds.Com Fat City Network Services -- 858-538-5051 http://www.fatcity.com San Diego, California -- Mailing list and web hosting services --------------------------------------------------------------------- To REMOVE yourself from this mailing list, send an E-Mail message to: ListGuru_at_fatcity.com (note EXACT spelling of 'ListGuru') and in the message BODY, include a line containing: UNSUB ORACLE-L (or the name of mailing list you want to be removed from). You may also send the HELP command for other information (like subscribing).Received on Tue Apr 01 2003 - 15:24:05 CST
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