Hi David,
Short Term: Look at the following:
- You may need additional indexes on your table. Also
remember that a compound index will not be used unless the first column in
the index appears in the where clause.
- Check for row chaining in your large tables. If this is a
problem determine why. One cause is row sizes that exceed your database
block size. If this is your problem you should seriously consider
redesigning the table (you might split it into multiple tables for example).
A second frequent cause of row chaining is rows that have little data when
they are inserted into the table and grow significantly due to update
activity. If this is the case you will have to save off the data, drop the
table, recreate it with revised PCTFREE and PCTUSED parameters, and then
reload the data.
- Is your database sized properly? You can find queries that will
allow you to monitor your database and its sizing. (a good STARTING point
is www.orafaq.org/faqmain.htm just follow the links you will find there and
you will come across the queries that you need).
- Others will provide some additional things you should look at.
I mention these because they are the ones that I have experienced in the
past.
Long Term:
Get some books on Oracle tuning and Kevin Loney's DBA Handbook
for the version of Oracle (7.x or 8.x) that you are using.
regards
Jerry Gitomer
David Novo wrote in message <7htvu7$2sa$1_at_talia.mad.ttd.net>...
>I have a lot of reads to a big table (about 800.000 records). I have only
>reads no writes.
>The CPU increased to 30%.
>
>
>What can I do, to optimize the performance, to decrease the CPU time ??
>
>Thanks!!
>
>
Received on Wed May 19 1999 - 14:43:19 CDT
