From the Oracle doco...
"v$rowcache: This view displays statistics for data dictionary activity.
Each row contains statistics for one data dictionary cache. "

This view shows the information which can be used to calculate the hit ratios for each area of the data dictionary cache.

Here are some links to various doco on both dictionary cache and utlbstat/utlestat

Tuning memory allocation: Ch19 of Oracle doco :
http://technet.oracle.com/docs/produ...2/ch19_mem.htm
Utlbstat/Utlestat
http://www.adsinc.com/whitepapers/UtlestatReport.html

Rule of thumb bad hit ratios may be a symtom of either a
1) too small shared pool
2) frequently used stored procedure not pinned.
3) Too much parsing i.e lack of bind variables.

Have Fun