Are you trying to eliminate URL encoded characters with the regex pattern in the where clause?
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April 11, 2018 at 7:10 am
            
#1986339

            
            
                                                
        

Quick thought, change the table from a heap to a clustered index table.
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This can be simplified to be done in the variable declaration statement.
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DECLARE @YEARMONTH  CHAR(7) = '2017-06';
DECLARE @PRIORYEARMONTH CHAR(7) = CONVERT(CHAR(7),DATEADD(YEAR,-1,CONVERT(DATE,CONCAT(@YEARMONTH,'-01'),120)),120);

I would suggest that you thoroughly analyse the problem before choosing the tools😉
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There are several limitations using memory-optimized tables, have a look here, SQL...

Quick thought, the return value of the TRY_CAST function is not used in the output of the query, maybe Steve should rewrite the query to support the explanation😉

There are quite few articles and blog posts on the subject, suggest you start with this one.
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