Q
Problem solve Get help with specific problems with your technologies, process and projects.

Capability of query optimizers in 8i

What is the capability of the query optimizers in each case (Oracle 8i and SQL Server 2000)? Can programmers change the query plan?

I can only answer about Oracle 8i since I do not have too much experience with SQL Server. Hopefully, your question can be posed to a SQL Server expert.

Oracle 8i & 9i have come a long way in improving their Cost Based Optimizers. If at all possible, you should let the system's optimizer determine the best execution plan. But this means keeping your statistics up to date.

If you wish to control your SQL execution in Oracle, then you can use hints in your SQL statement. For instance:

SELECT /*+ INDEX(table_a_pk) */ col1, col2, col3
FROM table_a
WHERE col1='somevalue';
The hint appears between the '/*+' and '*/' characters. This hint tells the system to use the specified index. There are many more hints available which you might want to look at in the Oracle 8i Performance Tuning Guide.

For More Information

  • What do you think about this answer? E-mail the editors at editor@searchDatabase.com with your feedback.
  • The Best Oracle Web Links: tips, tutorials, scripts, and more.
  • Have an Oracle or SQL tip to offer your fellow DBAs and developers? The best tips submitted will receive a cool prize. Submit your tip today!
  • Ask your technical Oracle and SQL questions -- or help out your peers by answering them -- in our live discussion forums.
  • Ask the Experts yourself: Our SQL, database design, Oracle, SQL Server, DB2, metadata, object-oriented and data warehousing gurus are waiting to answer your toughest questions.

Dig Deeper on Oracle database design and architecture

Have a question for an expert?

Please add a title for your question

Get answers from a TechTarget expert on whatever's puzzling you.

You will be able to add details on the next page.

Start the conversation

Send me notifications when other members comment.

Please create a username to comment.

-ADS BY GOOGLE

SearchDataManagement

SearchBusinessAnalytics

SearchSAP

SearchSQLServer

TheServerSide.com

SearchDataCenter

SearchContentManagement

SearchHRSoftware

Close