The SQL Scripts Used in This Topic - Expert Oracle RAC Performance Diagnostics and Tuning - page 646

Chapter 17—Waits, Enqueues, and Latches

No. Script Name Description

MVRACPDnTap_dlmlatch.sql 1 The script shows the number of times the latch was acquired by

sessions on one of the instances in a RAC cluster in an Oracle Database
12c Release 1 environment.

MVRACPDnTap_latchchildren.sql This script against the view V$LATCH_CHILDREN can help us arrive at the

address that has the highest miss rate.

2

MVRACPDnTap_hotsegments.sql The script helps identify the segments most often subject to cache

buffer chains latch statistics.

3

MVRACPDnTap_whoractivep.sql

4 The script helps list all the current active sessions and the process

information.

MVRACPDnTap_lockmodes.sql 5 The script helps list all the current lock modes for the enqueues on the

database.

MVRACPDnTap_enqstats.sql 6 The script helps understand the enqueue stats from the database.

MVRACPDnTap_rowcache.sql

7 The row cache statistics from the output helps to understand the

database configuration settings. The higher the refresh or reload
activity for a specific row cache item could be an indication one should
look at optimizing it, for example, in the case of sequences (identified
by dc_sequences ) to increase the cache size.

MVRACPDnTap_dlmrowcache.sql

8 This is a variation of the pervious query. The primary difference

between the two is from what level the data is reported. This query
reports data from a RAC level, across instances, and reflects cache
fusion activity.

MVRACPDnTap_lostblocks.sql 9 Blocks can be corrupted or lost during transfer across the interconnect.

This script helps determine the number of blocks lost/corrupted over
the interconnect since the instance was started.

Chapter 18—Problem Diagnostics

No. Script Name Description

MVRACPDnTap_HMChecksList.sql 1 Script lists all the currently configured health monitor checks.

MVRACPDnTap_hmparmlist.sql 2 Script provides a list of parameters required to execute the various

health monitor checks.

MVRACPDnTap_HMRunSatus.sql 3 Script helps check the status of the various health monitor checks.

MVRACPDnTap_HMfinding.sql

4 Script provides a listing of the findings from the health

monitor check.

MVRACPDnTap_adrproblemlist.sql 5 Script provides a summary of the currently encountered problems on

the various instances in the cluster.

( continued )