First take a look at srivenu's note.

There is a bug in some versions of 8.1.7 which
puts excess pressure on the latches covering
root blocks of indexes. Are any of your hot
index blocks the root block. (Check dba_segments
for the location of the segment header block, the
index root block is always the block after the
segment header block).

There is no reason why a hot block has to be a
table block. In fact, for latching reasons, index
blocks are more likely to get hot than table blocks
if the tables are popular lookup tables. (There are
more table blocks than index blocks usually, so the
so visits are spread out more thinly across the table).

If the problem is the root block problem, you may
need to upgrade. The other option is to find out why
you are doing so many lookups, and reduce the amount
of work. Index-related latch contention is sometimes
an indication of excessive reliance on indexed access
paths when the occasional tablescan might be more
cost-effective.


--
Regards

Jonathan Lewis

http://www.jlcomp.demon.co.uk

http://www.jlcomp.demon.co.uk/faq/ind_faq.html
The Co-operative Oracle Users' FAQ

http://www.jlcomp.demon.co.uk/seminar.html
Optimising Oracle Seminar - schedule updated May 1st


"hrishy" <hrishys@yahoo.co.uk> wrote in message
news:4ef2a838.0406020113.23c4f4e8@posting.google.c om...
> Hi Jonathan
>
> whe i run your query i see the hot blocks are for indexes..i was
> expecting tables there..now what i am kind of lost
>
> regards
> Hrishy
>