What I understand is that, we have to put all the values from the left table to the table variable, first. Then we have to UPDATE the table variable with the right table values. Then select from the table variable..
An insert and update (with joins) and a select to replace a select. Does that sound like an efficient option?
You still haven't answered the question. Are the left joins a problem (not does someone say they are)? Have you tested and determined that the LEFT keyword is causing such major performance problems?
If you haven't, you're wasting your time looking for a solution to what may well not be a problem
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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