Comments on: Contention

By: rnm1978

rnm1978 — Mon, 24 May 2010 10:29:22 +0000

Here’s the followup to the original story: http://www.guardian.co.uk/uk/2010/may/24/pedestrian-crossing-protest-traffic-superglue

By: Connor

Connor — Mon, 17 May 2010 04:51:27 +0000

“alter system kill pedestrian” would have handled the job nicely :-)

By: Daniel Stolf

Daniel Stolf — Sat, 15 May 2010 18:30:23 +0000

Once, there wad this application and it had a module with a pool of open connections the app would use to query the database, something like jboss, but made in-house.

This module made queries to keep the connections opened. The developer thought it would be a nice idea to select xxx.xx from dual several times per second, where xxx.xx is a any number between 000.00 and 999.99. I still don’t know if this number was random or incremental, but you can try and guess how it screwed the database :P

By: david

david — Sat, 15 May 2010 17:59:45 +0000

if you are a oracle DBA , you should have know this type of simulations in Oracle. Some times we can’t find long running one single sql, but DB CPU is high.
But even when optimized sql runs repeatedly , you face the same difficulty.

So even a small job, if repeated very frequently, there should be a LIMIT for it.