indexes

[dbaindi]

Hello Gurus
My requirement is

to quickly select records based on either the ID column or the LAST_NAME or both columns together from my table say 'T'

For this
I want to create index on these two columns

Should I be creating


1 index specifying both columns, or

2 indexes (one on each), or

3 indexes (one for ID + one for last name + both)

Can you please advice ??

Thanks in advance

[PAVB]

I'll start with one on each column.
Assuming ID column is unique the "two columns together" requirement will be serverd by the unique index on ID.