Solved

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

Posted on 2010-11-23
5
297 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 77

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 74

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
execute immediate plsql block 5 59
'G_F01' is not a procedure or is undefined 3 34
grant user/role question 11 32
sum of columns in a row in oracle 3 33
This article started out as an Experts-Exchange question, which then grew into a quick tip to go along with an IOUG presentation for the Collaborate confernce and then later grew again into a full blown article with expanded functionality and legacy…
From implementing a password expiration date, to datatype conversions and file export options, these are some useful settings I've found in Jasper Server.
This video shows how to Export data from an Oracle database using the Datapump Export Utility.  The corresponding Datapump Import utility is also discussed and demonstrated.
This videos aims to give the viewer a basic demonstration of how a user can query current session information by using the SYS_CONTEXT function

820 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