Solved

Performance tuning

Posted on 2014-03-06
6
307 Views
Last Modified: 2014-06-10
How do we know if we have to build a new index or gather statistics to improve the performance ...

Is there anyway, Oracle automatically gathers statistics or do we have to do it manually.
0
Comment
Question by:d27m11y
[X]
Welcome to Experts Exchange

Add your voice to the tech community where 5M+ people just like you are talking about what matters.

  • Help others & share knowledge
  • Earn cash & points
  • Learn & ask questions
6 Comments
 
LVL 77

Accepted Solution

by:
slightwv (䄆 Netminder) earned 168 total points
ID: 39911366
>>How do we know if we have to build a new index or gather statistics to improve the performance ...

It may sound simplistic but:  People complain?

Check the server:  Is a lot of CPU being used?  A lot of disk I/O, Memory?

If you are licensed for the Performance Pack in Enterprise Manager there are a lot of Advisors that will go through how your database is being used and make recommendations.

If you aren't licensed for it, StatsPack is a decent second place but requires you to go through the output and understand what you are seeing.

Many DBA's have their own things to look at.

I used to look in v$sql for disk reads and see what I could do about the SQL causing them.

>>Is there anyway, Oracle automatically gathers statistics or do we have to do it manually.

Look in the online documentation for your specific version of Oracle for he automatic maintenance window.
0
 
LVL 23

Assisted Solution

by:David
David earned 166 total points
ID: 39911589
Needing a new index.....  a study of the resource-intensive SQL statements (explain plans) should point out if people are doing full table scans.  Said tables are likely candidates for better indexing.  Improper use of block sizes, contention (locked rows), and parallelism are worth a look-over as well.

In 11g and higher, Oracle has eliminated the need for scripted stats updates, as slightwv alludes to.  Somewhat like Microsoft's services, the database is now self-aware when a table or index stats need to be checked.  There are numerous settings a knowledgeable DBA can tweak, but the old way of doing this is gone.
0
 
LVL 35

Assisted Solution

by:Mark Geerlings
Mark Geerlings earned 166 total points
ID: 39913762
Yes, In Oracle10g and 11g databases, Oracle will likely gather some statisics for you automatically.  Are these (default) statistics always the best ones for your database and your application/  Likely no.

What klnd of application do you have?  Is it purchased or custom?

Is it mainly transaction-processing or reporting (Data Warehouse)?

Are your init parameters adjusted for your hardware and application?
0
 

Author Comment

by:d27m11y
ID: 39940820
It is a custom application and OLTP environment.
0
 
LVL 22

Expert Comment

by:Steve Wales
ID: 40124009
This question has been classified as abandoned and is closed as part of the Cleanup Program. See the recommendation for more details.
0

Featured Post

Industry Leaders: We Want Your Opinion!

We value your feedback.

Take our survey and automatically be enter to win anyone of the following:
Yeti Cooler, Amazon eGift Card, and Movie eGift Card!

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

Suggested Solutions

Have you ever had to make fundamental changes to a table in Oracle, but haven't been able to get any downtime?  I'm talking things like: * Dropping columns * Shrinking allocated space * Removing chained blocks and restoring the PCTFREE * Re-or…
Shell script to create broker configuration file using current broker Configuration, solely for purpose of backup on Linux. Script may need to be modified depending on OS-installation. Please deploy and verify the script in a test environment.
This video shows information on the Oracle Data Dictionary, starting with the Oracle documentation, explaining the different types of Data Dictionary views available by group and permissions as well as giving examples on how to retrieve data from th…
Via a live example, show how to restore a database from backup after a simulated disk failure using RMAN.

752 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question