Using
Not In Example:
Select bookname from book
where publisherid not in
(select publisherid from publisher)
--------------------------------------------
Above query rewritten with Outer Join
Select bookname from book, publisher
where book.publisherid = publisher.publisherid (+)
and publisher.publisherid is null
NOT IN in (Oracle) SQL is expensive and that a way to overcome this problem is to collect the non-matching rows with an OUTER JOIN.Not In Example:
Select bookname from book
where publisherid not in
(select publisherid from publisher)
--------------------------------------------
Above query rewritten with Outer Join
Select bookname from book, publisher
where book.publisherid = publisher.publisherid (+)
and publisher.publisherid is null
Get More Query Optimization Tips: http://nimishgarg.blogspot.in/2012/10/query-optimization-tips-for-oracle.html
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