Typically, the advice on fill factor is “if it ain’t broke, don’t fix it”. But occasionally, you’ll find a database or even a server with a crazy default setting that just fills your disk and buffer pool without any real benefit. Here’s a nifty script to rebuild any tables and indexes to a fill factor of 100%.
non-clustered index
Key Lookup without an output column?
Performance tuning the other day, I was stumped by a query plan I was looking at. Even though I had constructed a covering index, I was still getting a Key Lookup operator in my query plan. What I usually do when that happens is to check the operator’s properties to see what its output columns are, so I can include those columns in my covering index.
Here’s the interesting thing: there weren’t any output columns. What happened?
sqlsunday.com 