In addition to my previous post, another best practice is to not use NOLOCK and READ UNCOMMITTED transaction isolation level.
Here’s an excerpt from a profiler trace
BEGIN TRAN UpdateMediaTables SET TRANSACTION ISOLATION LEVEL READ UNCOMMITTED DECLARE @BackupSetId int, @MediaSetId int, @LogDevName varchar(512) SELECT @MediaSetId = media_set_id FROM msdb..backupmediafamily AS bmf WITH (NOLOCK) WHERE substring(bmf.physical_device_name,5,36) = '80A2E6DE-3E95-4645-B476-09E37306FF8C' SELECT @BackupSetId = backup_set_id FROM msdb..backupset WITH (NOLOCK) WHERE media_set_id = @MediaSetId
So, not only do we have no consistency, but also a non–SARGable lookup.
I’ve updated my previous connect item to reflect this also.