oracle

The first visualization I will be working on is something I have been wanting for a while. I need a way to quickly show SQL Statement performance over time for 1 statement, especially to identify Execution Plan volatility. When researching performance problems I often need to quickly digest historical performance of a trouble statement - a statement that usually has run fine for years but now has started acting up.

I am throwing together a quickie Play Framework application for a DB process dashboard. I love Play. Its quick, powerful, and does a pretty good job of getting out of your way when you need it to.

But as a cutting edge open source app framework the documentation is sometimes a little behind the curve... Or assumes you are always using h2 for dev and mySQL for production.

Here are some tips on getting your new Play app to play nicely with Oracle via JDBC.

Make the JAR Available to your App

I have been checking out some usage patterns on a database I am migrating to Exadata. I won't go into the 'drop all of the indexes' herd mentality... but I would like to know what is really being used on this system so we can make some educated guesses about what is really needed. Luckily it is a DW / ETL type of application that has a comprehensive nightly refresh. Yes, a nice way of saying flush and fill. Well at least I know they touch _every_ important object _every_ night.

...well not yet...

An Infoworld article was released today describing an Oracle vulnerability. The SCN space can be exhausted via bugs or attackers exploiting bugs. Metalink doc: 1376995.1 [Bulletin : Information on the System Change Number (SCN) and how it is used in the Oracle Database] covers a technical description for what SCNs are used for.

You can use this query to find out how close you are to the SCN limit.