Donald K. Burleson
With over 250 Oracle parameters and thousands of metrics, it is no small
task for the Oracle administrator to zero-in on the most important measures
of the health of his or her Oracle database. Many database administrators
use the following list to get a general idea of the overall health of their
Data Buffer Hit Ratio Alert - This report alerts the DBA when the data
buffer hit ratio falls below the preset threshold.
Redo Log Space Requests Alert - If redo log space requests are greater
than 0, you may want to increase the log_buffer parameter.
Shared Pool Contention Alert - Enqueue deadlocks can indicate contention
within the shared pool, as well as locking-related problems.
System Waits Alert - This query interrogates the Oracle event structures
to locate events that may be experiencing excessive waits. If you
experience waits on latch free, enqueue, LGWR waits, or buffer busy waits,
you need to locate the cause of the contention.
Library Cache Misses Alert - This query looks for excessive library cache
miss ratios. When the library cache miss ratio is greater than .02, you may
want to increase the value of the shared_pool_size parameter.
Database Writer Contention Alert - This query checks Oracle for values in
summed dirty queue length, write requests, and DBWR checkpoints. When the
write request length is greater than 3 or your DBWR checkpoint waits, you
need to look at tuning the database writer processes.
Data Dictionary Miss Ratio Alert - This script alerts the DBA when
requests for data dictionary metadata are high. Increasing the
shared_pool_size parameter can sometimes relieve this problem.
Data Dictionary Object Alert - This report can reveal internal contention
within the Oracle data dictionary, as well as a high rate of requests for
text is an excerpt from "Creating
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