FreeLists / oracle-l / Basic SQL Query Plan Qs

[VIVEK_SHARMA <VIVEK_SHARMA@xxxxxxxxxxx>]

Folks

SQL Query:-

select ..
from DTD
where account_num='N1'
and tran_date='10-02-2005'

NOTE - DTD Table has 400,000 rows approx with ALL its Records having just 1 
Date Value '12-06-2005' (i.e. a date value which is NOT in the SQL Query)
DTD Table has multiple values of account_num but does NOT have the specific 
account_num 'N1' specified in the SQL Query.

Running on which of the following indexes will be most performing & why?

Index 1 - Unique index on (tran_date, some field2, another field3)
Index 2 - account_ num
Index 3 - (account_ num, tran_date)

Optimizer - CBO
Oracle 10.2.0.3

Cheers & Thanks

Vivek

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