Tuesday, December 27, 2005

Deprecate Oracle Control Files

The Oracle control file is an operating system file that Oracle relies upon for startup and recovery. The file is essential for Oracle operation, and it is not managed as a tablespace is managed - no transaction consistency or redo log on the changes to the file.

The pfile or spfile (commonly called initSID.ora) specifies the location of the control file. The instance uses the control file specified in the pfile/spfile to open the database.

Having an external file that is not managed like a typical oracle datafile (a datafile that backs a tablespace) adds complexity during backup and recovery. There are specific procedures for backing up and recovering a control file.

Database information in the control file is also contained in the SYSTEM tablespace. Oracle documentation suggests checking the error log for indications of inconsistency between the SYSTEM tablespace and control file. This implies they contain the same information.

It would be possible to have the pfile/spfile point to the datafile that backs the SYSTEM tablespace and start the database by opening the SYSTEM tablespace. Removing control files from the Oracle architecture seems to be straight-forward and would reduce complexity. DB2, Sybase, and MS-SQL don't have anything like the control file, so it is not a technical requirement.

One kink is that Oracle writes RMAN information to the control file. This information could stay in the control file or be moved to a new file (named rman history file?).
The control file has been around for so many years that Oracle likely sees no marketing advantage in removing it to clean up the architecture.

Sun Certification Discount Through January

To qualify for the 10% discount offer, purchase a qualifying Sun certification exam, assignment, or essay by January 31, 2006. Provide Priority Code WW26CXG at the time of purchase.

I have found Bill's books useful in the past.

Free study guide.

Monday, December 26, 2005

Web Cam Image Publisher

This software monitors a web cam and can upload images to a web site. It has many more features and is much more stable than the software shipped by Creative with their web cam. Free download.

Sunday, December 25, 2005

Microsoft Office Alternative

OpenOffice has been around for a few years. I mostly install it on unix systems, as the MS Windows systems usually have a site license for the Office Suite. OpenOffice install on unix is straight forward, and there are ports for many operating systems. Version 2.0.1 is available.

Sun is supporting OpenOffice through the StarOffice Suite.

Tuesday, December 20, 2005

Open Source Virus Scanner

We have been using the open source virus scanner ClamAV since 2004. It is multi-platform, with a web site specifically for the Microsoft Windows version. It has a scheduler to scan files and to download updates.
On XP, memory usage for the Windows background task is about 2,428K with a VM size of 14,408K.

Monday, December 19, 2005

Power Usage and Postgres

Sun has been moving to reduce power consumption in the data center. Anyone managing more than a dozen machines must be concerned about scalability and redundancy of their power and cooling. More efficient chips are good.

Sun also announced support for Postgres, which will encourage more companies to consider open source databases. Low end databases have become a commodity. Money can still be made in support, while licensing fees are under pressure.
Microsoft is trying the opposite by raising prices. Like GM and Ford have found, consumers may pay up for a couple years, but consumers will look for alternatives.