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Can a scalar function, for example MAX, be used in WHERE...
Posted: Tue Nov 19, 2013 2:16 pm
by Anjali Chopra
Hi,
The question is - can a scalar function, for example MAX, be used in WHERE clause for SELECT? Could anypone please guide on this.
Any help is appreciated.
Re: Can a scalar function, for example MAX, be used in WHERE
Posted: Wed Nov 20, 2013 12:49 pm
by Anuj Dhawan
Hi,
The answer is Yes, but there is a "but" to consder here - one should limit the usage of Scalar functions such as SUBSTR, CHAR, INT etc. in the WHERE clause. This is advised because if any scalar function is used for a column in the WHERE clause, the DB2 optimizer will not use a matching index column for the retrieval of the records from the table - and it turn, the response time of your LUW gets slow.
Re: Can a scalar function, for example MAX, be used in WHERE
Posted: Wed Nov 20, 2013 6:06 pm
by Anjali Chopra
Thanks Anuj - this helps a lot!
Re: Can a scalar function, for example MAX, be used in WHERE
Posted: Sat Apr 12, 2014 5:14 am
by maidy
Hello Anuj,
What do you mean by:
the response time of your LUW gets slow.
Linux, Unix and Windows?
Thanks!
Maidy
Re: Can a scalar function, for example MAX, be used in WHERE
Posted: Sat Apr 12, 2014 7:40 am
by Robert Sample
Logical Unit of Work