Optimization of query, version 8.0.5 of Oracle
DBAsupport.com Forums - Powered by vBulletin
Results 1 to 2 of 2

Thread: Optimization of query, version 8.0.5 of Oracle

  1. #1
    Join Date
    Jul 2003
    Location
    Sofia, Bulgaria
    Posts
    91

    Optimization of query, version 8.0.5 of Oracle

    I have to optimize a query with lots of EXISTS and NOT EXISTS clauses. I know that from 8i I can use HASH_AJ and HASH_SJ for that case, but the database is 8.0.5 and RULE based optimizer is used.
    All the columns in the EXISTS and NOT EXISTS are indexed, but the query is very slow, even if AUTOTRACE showing that physical reads = 0.

    Any ideas what can I do?

  2. #2
    Join Date
    May 2000
    Location
    ATLANTA, GA, USA
    Posts
    3,136
    If the sub query involves small table then you can use IN clause rather than EXISTS. This is a general rule. In order to understand your problem correctly, post the SQL and the explain plan output.

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  



Click Here to Expand Forum to Full Width