Re: Access Path Tuning

You probably knew it, but
In later versions of Oracle
both columns of the index
would still be used, although
the second column would not
be used as effectively as
it could be (unless you were in
Oracle 8.1 and had created
a function-based index ......)

Here's a thought for the future:
If you use Row Level Security,
you can't necessarily use explain
plan to work out how a query
would work, you can only look
at the trace file to find out how
it did work, because only the trace
file shows the results of attaching
the security predicate to the query !!

--

Jonathan Lewis
Yet another Oracle-related web site: http://www.jlcomp.demon.co.uk

michael_bialik_at_my-deja.com wrote in message <88pigr$qq9$1_at_nnrp1.deja.com>...
>Hi.
>
> It's not so simple.
> What happens when tou specify 2 index columns in where, but use a
> function over a second field:
>
> SELECT * FROM my_tab
> WHERE F0001 = 12 AND SUBSTR ( F0002,1,5 ) = 'ABCDE';
>
> You still going to see INDEX RANGE SCAN in EXPLAIN.
>
> But you are correct about the solution :
> only TKPROF gives you some CORRECT indirect data .
>
> HTH. Michael.
Received on Sun Feb 20 2000 - 14:58:03 CST