How much does that key cost? (plus sp_helpindex9)

OK, two in two days? What's wrong with me (is what Paul said) after he said – who are you and where is my wife? But, this one is a short one, specifically a follow-on to my prior post about "Disk space is cheap…" I did a bit of simple math on the internal overhead and […]

Foreign Keys can reference UNIQUE indexes (without constraints)

Something I learned while the SQL Server 2008 Internals book was in tech edit (thanks to our *awesome* tech editor Ben Nevarez – who, unfortunately, does not have a blog or anything…yet! (well, I'm hopeful)), was that you can use a FOREIGN KEY constraint to reference a UNIQUE index – one without a PRIMARY KEY or […]

When did SQL Server stop putting indexes on Foreign Key columns?

The title is a common question I've received in the past and I thought I'd take a few minutes to explain a bit about keys and indexes… This is by no means a lot of detail regarding relational theory, etc. but there are a few things that we should quickly review to make sure that […]