sql

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! Here is a quick proof of concept with the relevant columns:

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.

I normally get a lot of mileage out of Application Express interactive reports. Unfortunately there are some restrictions on the SELECT statements that can be used with them. Here is a demonstration of a technique I use when I want to add some interactivity to a plain old Apex report.

I will create a Select List dropdown that submits and refreshes the report data automagically. The value in the select list will be applied as a filter to the report when it refreshes.

1) Create the Select List

• Items -> New Item -> Select List
• Choose "Select List with Submit"
• Next