Examine the details of the Top 5 Timed Events in the following Automatic Workloads
Repository (AWR) report: What are three possible causes for the latch-related wait events?
A.
The size of the shared pool is too small.
B.
The buffers are being read into the buffer cache, but some other session is changing the
buffers.
C.
There are frequent logons and logoffs.
D.
Cursors are not being shared.
E.
A large number COMMITS are being performed.
Explanation:
A,C,D
http://www.dba-oracle.com/m_latch_row_cache_objects.htm
The latch: row cache objects Oracle metric latches protect the data dictionary.
The Row Cache Objects Latch is a correlated latch to the shared pool latch is the row cache objects latch. The purpose of this latch is to provide data protection for user processes that access the cached data dictionary area within Oracle.
A latch wait on a row cache object often means that there is a point of contention within the data dictionary. The row cache object latch can also indicate SQL with excessive hard parsing or excessive reliance on data dictionary information such as views row-level security, synonyms, etc. The general solution for row cache latch waits is to increase shared_pool_size.
Also A C D