ShowColumnUsage presents table columns in a format for you to see all constraints, indexes, and foreign keys affecting each column. You'll be shocked at how many errors you'll find in your constraints and indexes within seconds of running it. I never deploy to customers without running this first.
I'll walk you through it quickly. Create the proc in msdb and do the following to see the results for all tables:
exec ShowColumnUsage '%'
Notice that all constraints and indexes numbered 1 are clustered.
Now let's see all the botched indexes in msdb...
-- non-unique clustered index is in reverse order from the foreign key definition
-- seems illogical but maybe they have their reasons
exec ShowColumnUsage 'DTA_reports_querytable'
-- idx2 is a complete waste since pk1.1 has it covered
-- only makes sense in a few critical situations
exec ShowColumnUsage 'log_shipping_primary_secondaries'
-- ak2 and udx3 are equal so one is redundant
exec ShowColumnUsage 'log_shipping_primary_databases'
-- this one is just plain weird having an alternate key that is part of a primary key???
exec ShowColumnUsage 'sysdtspackages'
Now run it in your databases and fix errors you could never see before.
