Wednesday, April 13, 2016
On a recent project, we hit upon an interesting problem - the SQL indexing uniquifier.It seems to be one of those deep, dark SQL secrets that's been tucked away down the back of the sofa and forgotten about over several years; an obscure journey into SQL's data storage and indexing mechanisms!What is the SQL Uniquifier?In a nutshell, if you have a non-unique, clustered index on a SQL table, SQL server will automatically "uniquify" this for you! It does this by adding a hidden integer column that acts like an auto-incrementing identity ...