Custid - Number - Not NullSalute - varchar2(5) - Not NullTitle - varchar2(5) - Not NullFName - varchar2(5) - Not NullMName - varchar2(5) - NullLName - varchar2(5) - Not NullAddress - varchar2(5) - NullCity - varchar2(5) - Not NullPin - varchar2(5) - Not NullUseOrNot - varchar2(5) - Null (Y/N)
select * from customer where NVL(UseOrNo,'N') = 'Y'[/cde]It uses indexes on table which cause major cost and it may result in performance issue.This statement can be re-written without using NVL like this:select * from customer where UseOrNo = 'Y'The NVL prevents the use of the index on the Customer table and reduces cost of searching to negligible amount of time.AttachmentsOracle NVL ()
select * from customer where UseOrNo = 'Y'