SQL Query tuning Tips    1-Use Boolean function during the aggeration /calculation/comparing to avoid performance issues. & Avoid using case when statement in case data is very larger(1.5 cr records). 2-Select ONLY those columns in a query that are required. Extra columns which are not actually used, incur more I/O on the database and increase network traffic. 3-DISTINCT incurs an extra sort operation and therefore slows your queries down. 4-should not be any Cartesian product in the query unless there is a definite requirement (LOD Calculation In tableau ). 4-Use Union all instead of Union.UNION incurs an extra sort operation which can be avoided. 5-Avoid column alias name during the joining. 6-Use of the EXISTS operator where possible once a match has been found it can stop and avoid a full table scan(instead of IN) 7-Use equi-joins(comparing with = operator) whenever possible, they improve SQL efficiency. 8- Separate SQL statements for different tasks to avoid...