The client's database has a nightly maintenance job to reindex.
May not be frequent enough. May not update the stats needed.
Does SQL try to do something 'clever' with "If A Or B" that it can't do with "If A Else If B"? But if it's "just one of those (performance) things", so be it and thanks for your time!
No, other than the fact that B doesn't have to be run in the second case if A is true.
No this is not 'one of those performance things and so be it'. There will be a reason here, it's not obvious from just seeing an abstraction of the code. I asked for the plans and the wait types to try and ID why and tell you why. It's not a plain case of 'anyone who uses OR is an idiot'
Microsoft Certified Master: SQL Server, MVP, M.Sc (Comp Sci)SQL In The Wild
: Discussions on DB performance with occasional diversions into recoverability
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