Oracle Database statistics
Database statistics give information
about load types in a particular database and the resources the database
requires for use. Cumulative statistics and database metrics are two types of
data for statistics that an Oracle database collects. These resources may both
be internal and external, or they can either be internal or external.
Statistics are imperative when it comes to measuring how the database is
performing. The statistics are also useful when diagnosing problems related to
the performance of the database. In this case, the Automatic Database
Diagnostic Monitor (ADDM) is used.
Cumulative Statistics
Cumulative statistics refer to the
accumulation of the total value of given statistics from the time the instance
of an Oracle statistic was started. Examples of cumulative statistics in an
Oracle database include the total number of logins into the system. System
cumulative statistics, specific SQL statement statistics and session statistics
are the types of databases statistics that that are generated by the Oracle
database. Cumulative statistics for services and segments are also tracked by
the database.
The significant cumulative statistics
are stored in the AWR (Automatic Workload Repository). The cumulative
statistics values can be found in such views as V$SYSSTAT and V$SESSTAT. Upon
shutting down of the instance of the database, the values of cumulative
statistics for it are reset. The AWR maintains values and cumulative for a
great number of statistics except only at the level of the session. It does
this for a regular period resulting in a snapshot of AWR.
Database Metrics
Database metric is another statistical
data that is collected from an Oracle database. Database metrics focuses on the
rate at which a given cumulative statistics change. It involves measuring this
rate against a broad range of units such as a database call, time or
transactions. Values of metric can be exposed to some views of V$. In this
case, the values give the average during a small change in time, which is
usually sixty seconds. The Recent history of values of metric are available
from views of V$ but are also available from snapshots of AWR. After collecting
current statistics, Manageability Monitor (MMON), which is a process in the
background, keeps updating data every minute.
Similarities between
cumulative statistics and database metrics
Cumulative statistics is similar to
database metrics because they both use AWR snapshots (Automatic Workload
Repository) in their functionalities. These photographs are retained in the
repository for workload for typical eight days. Snapshots can also be created manually
but is often not necessary.
Both cumulative statistics and data
metrics are collected by Oracle databases. They are also both used to check and
compare the performance of a system within a particular period. This helps in
ensuring the errors on the system are dealt with accordingly and promptly. This
is done by comparing the AWR reports at different times. They both give
information about load types in a particular database and the resources the
database requires for use in their operation. Both cumulative and metrics focus
on the system performance and how it can be improved.
Differences between
cumulative statistics and database metrics
While cumulative statistics are those
that are collected over specified period, metrics is the rate at which these
cumulative statistics change. Database metrics use event class metrics, service
metrics, session metrics long duration and short duration metrics while
cumulative statistics make use of views such as V$ and MMON.
Question
2:
Oracle Diagnostic Pack
Oracle diagnostic pack gives a platform
for diagnosing performance of an Oracle database automatically and high-level
functionality for monitoring the system. The pack also offers availability and
performance reporting capability, a repository for centralized performance and
substantial aggregation of performance across the system. This is quite
significant in the simplification of the management of massive databases
(Oracle, n.d.). The most important features in this pack are:
Automatic Workload
Repository
The pack has an AWR, which contains statistics for operation are
recorded at regular specific intervals about a specified database and other
information that may be relevant. It forms the background for all management
functionalities an Oracle database by itself. A report of AWR that is generated
for the analysis of a period of poor performance helps a lot in looking at the
general performance of a database. This report is an important tool for many
database administrators.
Automatic Performance
Diagnostics
The diagnostic pack has an in-built performance diagnostic tool in the
database kernel which substantially simplifies the process of diagnosing
problems of the performance of a database. This tool is known as Automatic
Database Diagnostic Monitor (ADDM). ADDM begins the analysis of the database by
focusing on the activities that consume most of its time. The tool then finds
out the causes of problems with the performance of the database (Oracle, n.d).
This enables the database administrator to be able to attend to the most urgent
problems in the system with prioritization.
Performance
Monitoring
The monitoring of performance in the system is automated, and this gives
the system administrator as much information as they need to do their work. It
uses automated monitoring of the system environment as a whole and provides
them with the information required by the administrators (Habib, 2015).
Advanced
Event Notification
The pack has an extremely accurate and advanced system of notification. Hence,
the system administrators are notified when they have stepped out of their
desks. The notification is done through different mechanisms such as e-mails,
running of custom scripts and through the use of SNMP traps.
References
Habib,
O. (2015). Top 6 Database Performance Metrics to Monitor in Enterprise Applications.
Oracle,
(n.d.). Enterprise Manager Licensing
Information.
Sherry Roberts is the author of this paper. A senior editor at MeldaResearch.Com in legitimate paper writing services if you need a similar paper you can place your order for custom college essay services.
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