V$OBJECT_USAGE view empty.

This is a very old issue, but one that sometimes is hard to remember when needed. I tried to monitor index usage to get rid of some indexes which in my opinion are not in use. I implemented the traditional method of index monitoring:

Start monitoring the index.
alter index SchemaOwner.IndexName monitoring usage;

After a while, query the V$OBJECT_USAGE view.

select * from V$OBJECT_USAGE;

It came to my surprise that the view was empty. The reason ... I knew it some time back ... but I forgot. I googled and I found a very good reference from Alex Gorvachev, who went (more...)

Where is the password column from DBA_USERS in 11g?

Oracle 11g brought several security enhancements, as it is well known by the 11g users. On previous Oracle versions it was possible to query the DBA_USERS PASSWORD column to get the hashed password string. It was useful when someone tried to temporarily reset the user's password and restore it to its original value without actually knowing it.

The command:


it could take the hashed value from the DBA_USERS data dictionary view. However starting with Oracle 11g this column is null ... so where are we supposed to take this hashed value from?.


Reading the alert.log as a local table.

Reading the alert.log file is a must for the DBA. This is the primary source of information about the Database. The traditional way to read it is by means of any text based tool that can open the file and lets you take a look at it and look for specific text patterns. This requires access to the Operating System, which probably is something the DBA can take for granted at most shops. However, it happens that because of security issues, access to the Operating System is restricted ... sounds familiar? ... either you have someone to send you the file (more...)

Oracle Magazine Nov-Dec 2010

I want to thank Oracle Magazine for publishing the interview at the Peer-To-Peer section

Ref. http://www.oracle.com/technetwork/issue-archive/2010/10-nov/o60peer-176064.html

"Which new features in Oracle Database are you currently finding most valuable? Oracle Automatic Storage Management and the Volume Manager. Another nice feature is Secure Files, which improves performance, optimizes storage, and provides an additional security layer.

What advice do you have for those just getting into application development? When designing an application, seriously evaluate the amount of intelligence it’s going to manage. This will define the amount of coding, complexity, round-trips to the server, and scalability. And be aware (more...)

ORA-00942 Querying Tablespaces from Enterprise Manager

In order to meet the minimum security requirements, the SYSTEM user use must be restricted, only the actual DBA must have access to it. Other users requiring access to Enterprise Manager to monitor and "view" must be granted especific minimum privileges.
The SELECT_CATALOG_ROLE and the CONNECT roles are good enough to see most of the E.M. contents, but when trying to access the Tablespaces page from Enterprise Manager the ORA-00942 error shows up.
When tracing I discovered the query used to fill up the Tablespaces Page:

SELECT /*+first_rows */ d.tablespace_name, NVL(a.bytes / 1024 / 1024, 0), DECODE(d. (more...)