The ALTER INDEX SET FILLFACTOR command acquires AccessExclusiveLock table lock . Following are the locks ALTER INDEX SET FILLFACTOR acquires, the commands that are allowed to run concurrently with its lock AccessExclusiveLock and the commands that conflict with it. The list also includes the conflicting row locks if applicable
Commands concurrently allowed on the table with ALTER INDEX SET FILLFACTOR
Nothing is allowed to run concurrently with ALTER INDEX SET FILLFACTOR
Commands conflicting with ALTER INDEX SET FILLFACTOR on the table
e.g. If tx1 does a ALTER INDEX SET FILLFACTOR on the table then concurrently tx2 tries to do any of the following commands on the same table, tx2 will be blocked. Conversely, if tx1 executes any of the following commands and then tx2 concurrently tries to execute ALTER INDEX SET FILLFACTOR, tx2 will block.