The shared pool is one of the memory structures in SGA. It is comprised of the data dictionary and the library cache. Check v$sgastat. The data dictionary cache buffers data dictionary objects that contain data about tables, indexes, users and all other objects. The Library Cache/SQL Cache buffers previously executed queries, so that they need not be reloaded and reparsed if user calls them again. Otherwise if the information is not in the buffer then oracle must get it from disk. The V$LIBRAY CACHE View stores performance data for library cache and V$rowCACHE view stores performance data for the data dictionary cache. Sometime we may have to increase the value of initialization parameter SHARED_POOL_SIZE.
To improve the performance .
