Solved

How to change an existing database from rule based optimizer to cost based optimizer

Posted on 2010-11-23
5
295 Views
Last Modified: 2012-10-06
Hi can anyone tell me how we can change existing Database which is running on Rule based optimizer converting it to cost based optimizer.
0
Comment
Question by:iabhinay_dba
5 Comments
 
LVL 76

Assisted Solution

by:slightwv (䄆 Netminder)
slightwv (䄆 Netminder) earned 166 total points
ID: 34202070
The optimizer_mode init parameter.  On mobile so I can't provide an exact link but it's in the online docs.
0
 
LVL 73

Accepted Solution

by:
sdstuber earned 168 total points
ID: 34202361
http://download.oracle.com/docs/cd/E11882_01/server.112/e17110/initparams167.htm#i1131532

It's not documented after 9i but you can also set the value to "CHOOSE"
0
 
LVL 5

Assisted Solution

by:anand_20703
anand_20703 earned 166 total points
ID: 34273639
Above answer is right and CHOOSE parameter is recommended because optimizer will select between RULE and COST , accordingly generates the explain plans. RULE based optimizer is old and was recommended only in Oracle ERP applications older than 11i.
.
To reap the benefits(performance) of  COST/CHOOSE optimizer enabled Databases, gathering statistics periodically is very important.
0

Featured Post

PRTG Network Monitor: Intuitive Network Monitoring

Network Monitoring is essential to ensure that computer systems and network devices are running. Use PRTG to monitor LANs, servers, websites, applications and devices, bandwidth, virtual environments, remote systems, IoT, and many more. PRTG is easy to set up & use.

Question has a verified solution.

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

Suggested Solutions

Title # Comments Views Activity
compre toata in where clue oracle 4 57
How can I rollback insert statements after commit in oracle? 7 65
Oracle Pivot Question 8 45
su - oracle could not open session 6 53
Truncate is a DDL Command where as Delete is a DML Command. Both will delete data from table, but what is the difference between these below statements truncate table <table_name> ?? delete from <table_name> ?? The first command cannot be …
How to Unravel a Tricky Query Introduction If you browse through the Oracle zones or any of the other database-related zones you'll come across some complicated solutions and sometimes you'll just have to wonder how anyone came up with them.  …
Via a live example show how to connect to RMAN, make basic configuration settings changes and then take a backup of a demo database
This video shows how to copy a database user from one database to another user DBMS_METADATA.  It also shows how to copy a user's permissions and discusses password hash differences between Oracle 10g and 11g.

863 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

Need Help in Real-Time?

Connect with top rated Experts

20 Experts available now in Live!

Get 1:1 Help Now