Skip to Main Content
Forums

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!

index creation online - performance impact on database

1061104Dec 18 2013 — edited Dec 18 2013

hi,

I have oracle 11.1.0.7 database running on Linux as 3 node RAC.

I have a huge table which has more than 255 columns and is about 400GB in size which is also highly fragmented because of constant DML activities.

Questions:

1. For now i am trying to create an index Online while the business applications are running.

Will there be any performance impact on the database to create index Online on a single column of a table 'TBL' while applications are active against the same table? So basically my question will index creation on a object during DML operations on the same object have performance impact on the database? is there a major performance impact difference in the database in creating index online and not online?

2. I tried to build an index on a column which has NULL value on this same table 'TBL' which has more than 255 columns and is about 400GB in size highly fragmented and has about 140 million rows.

I requested the applications to be shutdown, but the index creation with parallel of 4 a least took more than 6 hours to complete.

We have a Pre-Prod database which has the exported and imported copy of the Prod data. So the pre-Prod is a highly de-fragmented copy of the Prod.

When i created the same index on the same column with NULL, it only took 15 minutes to complete.

Not sure why on a highly fragmented copy of Prod it took more than 6 hours compared to highly defragmented copy of Pre-Prod where the index creation took only 15 minutes.

Any thoughts would be helpful.

Thanks.

Phil.

Comments

morgalr

That is a lot of code to go through, so I am not.

Let me ask you this:  I see you have a portion that is marked as recursive, do you recursively call the loading of the images?  If you do therein is your problem.

RuGI:.

Have you tried to define your Layout at  level of the class as static attribute?
You only require one.


Each time you use a BufferedImage, after painting the image invokes flush


picture.flush();

picture = null;

---

RuGI

Max8090-JavaNet

Thanx for the answer.

Can you tell me, which lines are recursive?

It was not my intent to do a recursive call. If so, this could maybe the problem.

Max8090-JavaNet

Yes, but didn't help.

Max8090-JavaNet

The problem is solved. I don't use the class OverlayLayout anymore. The layout looks quite different, but now it works.

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

Post Details

Locked on Jan 15 2014
Added on Dec 18 2013
#general-database-discussions, #index
4 comments
2,160 views