Saturday, December 03, 2011

Oracle Database 11g Release 2 Upgrade Seminar

I went to an Oracle seminar at CPC Venues in London recently. It explained how and why you should move to Oracle 11g release 2. The speakers were Mike Appleyard, John Nangle and Peter Alsop. It was extremely well done and, if you get the chance, you should go on it.

When I returned to work, I asked for a copy of the slides from the presentation and they sent me a link to download them a few hours later.

I decided to try out a new feature, which allows you to use solid state disk storage to extend your database's buffer cache. I then found a test database running on 11g release 2. Unfortunately I did not have a solid state disk to hand so I had to make do with an ordinary one.

To use this feature, you need to add two new parameters to your init.ora file. This is the first one:

db_flash_cache_file='/export/home/oracle/andrew/ssd'

It gives the name of a file on a solid state disk, which will be used as the buffer cache extension. Oracle creates it if it does not exist.

The second parameter gives the size of the file:

db_flash_cache_size=10m

Then I bounced the database:

11gR2 > sqlplus / as sysdba

SQL*Plus: Release 11.2.0.1.0 Production on Fri Dec 2 18:24:58 2011

Copyright (c) 1982, 2009, Oracle.  All rights reserved.

Connected to:
Oracle Database 11g Enterprise Edition Release 11.2.0.1.0 - 64bit Production
With the Partitioning, OLAP, Data Mining and Real Application Testing options

SQL> startup force
ORA-01078: failure in processing system parameters
ORA-12427: invalid input value for db_flash_cache_size parameter

SQL>

This failure did not come as much of a surprise as the notes from the presentation suggested a size of 120 gigabytes! I tried again with a size of 100m and the database opened OK.

This is the file which Oracle created:
 
11gR2 > pwd
/export/home/oracle/andrew
11gR2 > ls -l ssd
-rw-r-----   1 oracle   dba      104857600 Dec  2 18:08 ssd
11gR2 >

That's as far as I can go with this new feature for now. Once I have a solid state disk, I will try it out properly and report my findings.

In the meantime, I will read through the slides from the presentation, try out some other new features and let you know how I get on. 

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