query using index get no row?

I had this two queries:

select * from table where id = number;
select /*+ NO_INDEX (table PK_IDX)*/ * from table where id = number;

When query used index no row was returned. Index is on primary key column and status in user_indexes was 'VALID'.

I rebuild index but problem is not fixed.

I fixed problem with:
 alter index PK_IDX unusable;
and then
 alter index PK_IDX rebuild;

What was problem?

Goran Received on Fri Apr 18 2008 - 03:24:09 CDT