Difference between NOT IN and exists in sql server?

Hi,

 not in can also take literal values whereas not exists need a query to compare the results with. EDIT: not exists could be good to use because it can join with the outer query & can lead to usage of index, if the criteria uses column that is indexed. EDIT3: Let me take the above things back 

depending on the amout of data been used , some cases the IN clause doesn't use the table indexes

 

https://stackoverflow.com/questions/31500/do-indexes-work-with-in-clause

 

https://stackoverflow.com/questions/1597442/subquery-using-exists-1-or-exists

Hello,

 

EXISTS - will tell you whether a query returned any results

 

NOT IN - gives the unmatched records when compared with more than one table

 

IN - is faster than EXISTS, when the sub-query results is very small

 

Thanks.