RMAN Backup With Compression

I repeated the test from the previous post but this time I tried to compress the backup. At this stage I need your help. I believe I have used the free compression which does not require an extra licence. If somebody who knows more about this than me could add a comment below, telling me if I am right or wrong, that would be very helpful. I backed up the database as before:

C:UsersAJ0294094>rman nocatalog (more...)

RMAN Backup Without Compression

I wanted to test the effect of RMAN backup compression on an Oracle database running on Windows. I configured the flash recovery area, closed the database and mounted it. Then I did a backup without compression:

C:UsersAJ0294094>rman nocatalog target=andrew/reid

Recovery Manager: Release - Production on Fri Mar 11 18:42:42 2016

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connected to target database: (more...)

Creating Tables in the UNDO Tablespace??

I was reading an article written by Martin Widlake in Oracle Scene Issue 58 (Autumn/Winter 2015). It said:

The second new item is the UNDO tablespace. This is a special tablespace that is only used for internal purposes and one that users cannot put any tables or indexes into.

This seemed perfectly reasonable so I wondered what might happen if I tried to do it. In an Oracle database Oracle returned (more...)


I went on my first DBA course in 1997 and the lecturer there explained that readers do not block writers in an Oracle database. I had an issue recently which appeared to contradict this so I have reproduced it below in an Oracle database.
I noticed in OEM that there was some issue in the database. As usual, click on the images to enlarge them and bring them into focus (more...)


This post is an update to an earlier one, which I have now deleted. I tested the first part of it in an Oracle database. First I created a role which was identified by a password:
SQL> conn / as sysdba
SQL> create role low identified by secret_password
  2  /
Role created.
I granted the role to a user and made sure it had (more...)

DBMS_STATS Causes ORA-00600 [15851]

| Apr 3, 2013
I noticed this in an Oracle database. DBMS_STATS failed with an ORA-00600 and the first argument was [15851]. On investigation, it seemed to have something to do with the fact that the table had a function based index: