RE: query and delete records really slow in a table

  • From: "Igor Neyman" <ineyman@xxxxxxxxxxxxxx>
  • To: <legedoos@xxxxxxxxx>, <oracle-l@xxxxxxxxxxxxx>
  • Date: Fri, 19 Oct 2007 09:24:01 -0400

Do you have indexes supporting your foreign keys?

Igor 

-----Original Message-----
From: oracle-l-bounce@xxxxxxxxxxxxx
[mailto:oracle-l-bounce@xxxxxxxxxxxxx] On Behalf Of LegeDoos
Sent: Friday, October 19, 2007 8:29 AM
To: oracle-l@xxxxxxxxxxxxx
Subject: query and delete records really slow in a table

Hi there!

We have a couple (18) of tables "linked" with foreign keys and cascading
delete. The largest table contains < 1.000.000 records.

When deleting a record from the top level table, this is extremely slow
(like waiting a couple of minutes). On another database (on the same
server and on another server) deleting is fast (<1sec). Tables contain
defferent data.

-There are no blocking locks
-rebuilding the indexes didn't help
-the explain plan looks ok and is the same for the different databases

0               DELETE STATEMENT optimizer=ALL_ROWS (cost=460 card=1
bytes=73)       
1       0         DELETE of 'OST_STUDENT_STUDIEVOORTGANG'       
2       1           HASH JOIN (SEMI) (cost=460 card=1 bytes=73) 
3       2             TABLE ACCESS (FULL) of
'OST_STUDENT_STUDIEVOORTGANG' TABLE
(cost=57 card=31859 bytes=1146924)
4       2             TABLE ACCESS (FULL) of 'OST_STUDENT_EXAMEN' TABLE
(cost=199
card=55431 bytes=2050947)

-I moved all tables en indexes to another tablespace, didn't help -There
are no errors in the alert.log.

Can anybody help?

Thanks!

Rob
--
//www.freelists.org/webpage/oracle-l



--
//www.freelists.org/webpage/oracle-l


Other related posts: