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I need to execute an SQL query.
If i have a query with multiple tables in From clause with Join condition in Where clause,
And i have Group by statement,
Should i perform Join operation first followed by Group By ?
OR should i perform Group By first then Join ?
Which one would be better ?
Note: In my environment, whichever operator that filters out more tuples should be executed first for better performance and less usage of memory for overall query execution.
Use DB’s EXPLAIN syntax, You’ll see witch of this two methods (in Yours specific environment) will cause more DB operations taken to produce output