Just how effective is Hybrid Columnar Compression? This test shows that HCC is impressive, but that thought needs to be put into choice of compression algorithm.
I first came across partitioning with release 7, when it didn't exist. Like many DBAs, I simulated it by writing a lot of application code. You can still do this – and you may have to if you haven't bought Enterprise Edition plus the partitioning option. Here's another way to do it, with partitioned views.
The cost based optimizer makes decisions that can be hard to understand. One of the hardest may be why it chooses indexed or scan access paths: a burning question for many DBAs.
I would like to share something about ORACLE_SID registry parameter.
I had a chance to restore (RMAN) a database on a new Windows server. The restoration/recovery was completed and there was no issue in logging to the database from the server.
The only thing I had to do was to set the ORACLE_SID variable everytime using the statement "set ORACLE_SID=abcd". I will encounter the error "ORA-12560: TNS:protocol adapter error".
Proxy authentication has been around since release 9i, but it isn't widely used. It can be a very useful facility for giving certain users access to high privileges without having to give them any direct grants or roles, and avoids many of the problems of using shared accounts. It is of course fully audited.
Following previous blog re BASIC compression, here are a couple of simple tests with Advanced Compression - which is supposed to survive conventional DML.
