Use of option (merge join)

Question

Why we use option (merge join). But using this my sql query response very fast. can anyone explain in simple words.???

Jignesh Trivedi · Answer

hi The merge join used to generate data from two sorted data set using inner lert and full join. here joined columns must have match data type with each other i.e. we cannot join numeric data type with charater data type column. merge join ifself very fast it can be expensive choice if sort operations are required. Please refer http://technet.microsoft.com/en-us/library/ms190967(v=sql.105).aspx http://gullimeelsqlsybase.wordpress.com/2012/06/26/improved-merge-join-algorithm-in-sql-server-2008/ hope this will help you.