Aaron Bertrand walks us through a painful scenario:
We recently performed a DDL operation against a SQL Server table – simply increasing the size of a varchar column – which should have been instantaneous. Instead, we killed the SQL Server process after observing 20 minutes of HARD_SYNC_COMMIT waits and a blocked replication log reader. Could this issue have been avoided? What went wrong?
I spotted the issue pretty quickly, but it’s easy to miss in a code review. Read the whole thing.