GoSelector

Database Column Selectivity is used as a guide by SQL Engine to influence choice of indexes for queries. Implemented values maybe have already been added to distributed code for example by:

Do $SYSTEM.SQL.Stats.Table.SetFieldSelectivity("TEST","PropertyLen2","T1","5.1%")

Affects class storage definition adding:

<Property name="T1">
<Selectivity>5.1%</Selectivity>
</Property>

This scheduled Task:

• Does NOT modify Table / Class definitions
• Extracts existing column selectivity values found in an environment
• Profiles corresponding data values
• Generates a report of Column implemented selectivity versus actual ratio of distinct values
• Is not intended to replace or compete with other utilities

Can Use Task Schedule Output file option to create report file.

set task=##class(alwo.GoSelector).%New()
set task.ClassNamePattern="1""TEST."".E"
do task.OnTask()

Hope this utility may inspire reuse for other developer reporting needs.