Points to Consider While Writing Queries - Microsoft SQL Server 2012 Performance Tuning - page 275

There's more...
Apart from the points we have discussed in the chapter, there are few more common points
to keep in mind while writing the query, here is the list of the same which are helpful in
performance gain.
F Specifying as many possible filters in the query, to all the tables participating in the
query, even if the filter looks straightforward
F Avoid using the ORDER BY clause, if not needed
F Have smaller items in GROUP BY and make sure that they are from the same tables,
if possible
F Have integer values in GROUP BY and not strings, if possible.
F Have columns from the same table in GROUP BY and in ORDER BY , if possible.