We use strict mode in Hive to avoid performing full scan of a table in a query. It is very useful when we have a very large table. We can use ‘set hive.mapred.mode=strict’ command to put Hive into strict mode. In this mode, any query that needs full table scan will throw error to user.
Strict mode is a useful option in Hive to improve performance and avoid any unexpected delays due to full table scan.Read the full book at www.amazon.com