Turkish Oracle User Group’s largest annual event, TROUG Day 2011 will take place at 21th of April 2011 in Bahcesehir University, Istanbul. Jonathan Lewis will give the keynote presentation titled “How to Optimise… a two table join”. He’ll give a talk about techniques that are not available to the Oracle optimizer.

As a founding member of Turkish Oracle User Group, I’ll also be presenting at the TROUG Day. I’ll speak about Oracle Enterprise Manager Grid Control.

Agenda of TROUG Day 2011:

09:00-10:00 How to Optimise… a two table join Jonathan Lewis
10:00-10:50 Exadata in 20 Questions Ferhat Şengönül & Hüsnü Şensoy
10:50-11:00 Coffee Break
11:00-12:00 Enterprise Manager 11g Grid Control Gökhan Atıl
12:00-13:00 Lunch Break
13:00-14:00 Oracle Dataguard – How can we use it more effectively? Emre Baransel & Ogan Özdoğan
14:00-14:50 ASM Best Practices Orhan Bıyıklıoğlu
14:50-15:00 Coffee Break
15:00-16:00 Oracle 11g Backup & Recovery New Features Kamran Agayev & Zekeriya Beşiroğlu

Information about the conference packages can be found at TROUG web site: http://www.troug.org

We have a mirror MS SQL Server. We drop and re-create database snapshots on this server on every 2 hours. These snapshots are read-only because of the nature of the snapshot technology, so they can be used only for reporting, and that’s what we use them for.

Sometimes, dropping these snapshots takes a long time (such as 2.5 hours). Here’s a sample:

I wonder how and why does Ms SQL Server rollback transactions on a read-only/snapshot database! Even we assume that server is rolling back the internal transactions on tempdb, how could it take so long?

Ferhat Şengönül, Gürcan Orhan and I, as members of TROUG (Turkish Oracle User Group) will be in Sakarya University to present in IT Festival organized by Computer Science Community at March 24th. We will share our experience & knowledge about Oracle Technologies.

Here’s the schedule:

10:00 – 10:50 How To Become an Oracle DBA Gökhan Atıl
11:00 – 11:50 Datawarehouse and ETL Gürcan Orhan
12:00 – 14:00 Launch Break
14:00 – 14:50 DBA in Business Life Ferhat Şengönül
15:00 – 15:50 Questions and Answers Panel

You can use Monitoring feature of Oracle to find which indexes are unused. You can run the following query to enable monitoring on an index:

ALTER INDEX index_name MONITORING USAGE;

After you enable indexing, you should wait for a while (for example 1-2 days if you think that this index should be used daily), and then you can query v$object_view to see if index is used:

You can run the following query to disable monitoring of an index:

ALTER INDEX index_name NOMONITORING USAGE;

Disabling monitoring an index, does not change the “used” value on v$object_usage; If you query that view, you should still use the index as used. Because the “used” property shows if index is used between start_monitoring and end_monitoring period.

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SYS and SYSTEM users have DBA roles so they manipulate any object on database, but if you are using an Oracle DB prior to 9.2, you’ll see that DBA role is not enough to manipulate the privileges of other users’ objects.

Because before Oracle 9.2, there was not a system privilege called “GRANT ANY OBJECT PRIVILEGE”. For example, you can not run the following query on Oracle 8i (even with SYS):

Here’s a trick to overcome this problem: We create a temporary procedure under the target schema:

After we grant the required privileges, we can drop the procedure: