Re: Weird behavior of the table with unique index

A copy of this was sent to Alla Gribov <agribov_at_uptick.com> (if that email address didn't require changing) On Sun, 07 Feb 1999 17:49:38 -0500, you wrote:

>Hello, all;
>
>I am having a weird problem with a simple SELECT statement, that I've
>never seen before.
>
>I have a table, that has two columns as a primary key (which is an
>unique index). Table is kind of big (around 300,000 rows).
>
>Let's say that primary key is (COLUMN1, COLUMN2).
>
>I am running "Explain plan" on a following statement
>SELECT * FROM TABLE
>WHERE COLUMN2 = lv_column2
> AND COLUMN1 = lv_column1
>
>Explain plan shows me "Full table scan" instead of "Unique index scan".
>

what are lv_column2 and lv_column1? are they columns of the same TABLE? if so, an index could never be used as lv_column1 and lv_column2 are not constants. Every row would have to be inspected to see if that rows column1, column2 = lv_column1, lv_column2 for that row.

Need more info it lv_column1 and lv_column2 are not in the same table as the above query would indicate they are....

>Even if I put a hint on this unique index, I am getting "Full index
>scan"
>
>Any ideas?????????????????????
>
>
>Thanks for your help
>
>Alla
>
>P.S. Version of Oracle used is 7.3.3.
 

Thomas Kyte
tkyte_at_us.oracle.com
Oracle Service Industries
Reston, VA USA

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