Indexes

[kiss07]

Hi,

what is the use of Function based indexes.?
compare to revere index ,which index is better? .

Expecting replies..


Arun..

[debasisdas]

function based means rather than a particular column/column combination the function is used only if a particular function is used on the column

like UPPER

[debasisdas]

FUNCTION BASED INDEX
=============== =======

CREATE INDEX FUNINDEMP ON EMP(UPPER(ENAME));

NOTE:--INSTEAD OF CREATING THE INDEX ON THE COLUMN IT CREATES INDEX ON THE COLUMN EXPRESSION.


in the above sample example the index will be used if the UPPER function is used on the ENAME column in the sql query.