Submitted by dmann on Thu, 05/30/2013 - 17:59
I have a case where I need to enforce uniqueness on a combination of columns but only when a flag is set (ACTIVE_FLAG=1). The table also holds history and may have multiple inactive records mixed in but I don't want to keep those from being added to the table.
This can be done by exploiting the fact that null index expressions are not indexed. DECODE and function based index to the rescue!
Submitted by dmann on Wed, 03/13/2013 - 18:06
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. Read more about "Playing" Nice with Oracle - Using Play Framework 2.1 with Oracle
Submitted by dmann on Sat, 12/22/2012 - 09:16
Submitted by dmann on Wed, 10/24/2012 - 23:50
Submitted by dmann on Tue, 10/02/2012 - 12:25
I am evaulating some schema migration tools for a project I am working on. I want some basic help organizing scads of changes that we will make during development. I also want the ability to produce generic SQL scripts as output to pass along for review / execution by folks that are not knee deep in our development environment.
The SQL Script output requirement cut out a lot of options. For a comprehensive list of options check out the feature matrix on the Flyway page which compares 9 popular schema migration tools.
Read more about myBatis Migrations and Oracle RDBMS
Submitted by dmann on Thu, 08/09/2012 - 14:44
Submitted by dmann on Mon, 07/30/2012 - 13:02
Submitted by dmann on Wed, 07/25/2012 - 13:03
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.
Read more about V$OBJECT_MONITORING gotcha...
Submitted by dmann on Tue, 07/24/2012 - 12:01
Submitted by dmann on Wed, 07/11/2012 - 05:16
I posted my GoldenGate / Gnuplot lag time alerting shell scripts to a new GitHub repository: http://github.com/dmann99/ggtools
The scripts worked on v8 and I don't think the INFO ALL screen has changed much since then so hoping it will work on v11 with a minimum of changes. I will post a more comprehensive walkthrough after I verify the v11 compatibility...
I also have an Alerting perl script that I will be tidying up and including in the ggtools repository ... but that won't be available until later this month. Read more about Golden Gate Lag Graph + Alerting scripts on the way...