Skip to Main Content

Oracle Database Discussions

Announcement

For appeals, questions and feedback about Oracle Forums, please email oracle-forums-moderators_us@oracle.com. Technical questions should be asked in the appropriate category. Thank you!

Interested in getting your voice heard by members of the Developer Marketing team at Oracle? Check out this post for AppDev or this post for AI focus group information.

supplemental logging

user10394804Nov 16 2009 — edited Nov 16 2009
Hi all,

Can someone help me in knowing the performance or any other kind of over-head by enabling supplemental logging in PRODUCTION database.

Thanks in advance

Comments

JustinCave
As with anything else, it depends. You would need to enable it in your test environment (assuming your test environment properly simulates your production environment) and test what overhead you observe given your hardware, your workload, and exactly what supplemental logging you enable.

In general, the performance overhead is not noticable. But if you have an I/O system that is approaching saturation, any additional I/O may cause severe performance problems. If you decide to supplementally log a large number of additional columns on every table, that can also be problematic.

In determining the overhead, though, you also need to think about the alternatives. Presumably, you are thinking about enabling supplemental logging for some purpose. Assuming you have, for example, a business requirement to do replication, and you are looking at supplemental logging so that you could use Streams, the alternatives would almost certainly involve a larger overhead because Streams is designed to be a low impact replication solution.

Justin
Deepak_DBA
hi,


supplementary logging is mainly ment for DR, replica or streams, to enable it in prod is not advisable..if you have les io and less upadates, then its ok .. but try it in your test enveroinment, and see the efficiency then do in Prod.. but supplementary logging doesnot support some datatypes too..



regards,
Deepak
JustinCave
Deepak_DBA wrote:
supplementary logging is mainly ment for DR, replica or streams, to enable it in prod is not advisable..if you have les io and less upadates, then its ok .. but try it in your test enveroinment, and see the efficiency then do in Prod.. but supplementary logging doesnot support some datatypes too..
Why would you say that it is not advisable to have supplemental logging enabled in production? As you indicated, supplemental logging is necessary for things like Streams. Unless you are saying that technologies like Streams should not be enabled in production, I don't understand the objection.

Justin
user10394804
Hi

Thanks for the updates.

My requirement is to monitor all the DML been executed in the database.

From a metalink note I found that supplemenatry logging needs to be enabled for storing session info in v$logmnr_logs

This is why we thought of enabling supplementory logging.

Ours is Oracle 11i ERP instance where insert,update and delete are happening very frequently

Thanks
Deepak_DBA
hi,

AS told test in the test serverand see the performance and all your requirements and then apply in the prod server.. no issues..



regards,
Deepak
1 - 5
Locked Post
New comments cannot be posted to this locked post.

Post Details

Locked on Dec 14 2009
Added on Nov 16 2009
5 comments
402 views