How do you read AWR?

Joe Ford

How do you read AWR?

Reading the AWR Report The main sections in an AWR report include: Report Summary: This gives an overall summary of the instance during the snapshot period, and it contains important aggregate summary information. Cache Sizes (end): This shows the size of each SGA region after AMM has changed them.

What is AWR report in performance testing?

The Oracle’s Automatic Workload Repository (AWR) collects, processes, and maintains performance statistics for problem detection and self-tuning purposes. The report generated by AWR is a big report and it can take years of experience to actually understand all aspects of this report.

What do AWR reports look for?

Analysis AWR Report

  • DB Time(s): Sessions elapsed time in the database.
  • DB CPU(s): Sessions elapsed time in the CPU.
  • Redo Size: Redo size ( byte ) between two snapshot.
  • Logical Reads: Logical read count in the database.
  • Block Changes: Block changes count between two snapshot.

What AWR report contains?

The AWR provides a set of tables into which snapshots of system statistics are stored. Generally these snapshots are taken on an hourly basis and include wait interface statistics, top SQL, memory, and I/O information that is cumulative in nature up to the time of the capture.

What is the difference between AWR and ASH report?

The Name of this reports describe what is the major difference between it and AWR , The ASH contains recent information on active sessions sampled every second. The AWR are taken every one hour and its one hour old will not help in diagnosing issues that are current on the database.

What is DB time in AWR report?

The DB Time is a time model statistic that is the sum of all Oracle process’ CPU consumption plus the sum of non-idle wait time. This “time” in AWR is the same as DB Time and it is the same as the DB Time statistic name in v$sess_time_model and v$sys_time_model.

How do I run AWR miner?

Basic Instructions

  1. Install R 3.x+
  2. Install RStudio.
  3. Open R-AWR-Mining.R file in RStudio.
  4. Set the working directory to the location of the .out or .out.gz files in RStudio via the “Session” menu > “Set Working Directory”.
  5. “Source” the R-AWR-Mining.R in RStudio via the Source button in the top+right or press ctrl+shift+s.

Where is AWR report saved?

ยง AWR Report: In Oracle 10g, this is the latest time-series report, and it is produced by running a SQL*Plus script in the $ORACLE_HOME/rdbms/admin directory. awrrpt. sql is a text-based report.

Does Awr capture all SQL?

– When statistics_level=all, AWR will capture the top 100 SQL for each of the criteria (elapsed time, CPU, disk reads, etc.), for a total of 1400 SQL statements per snapshot. Of course, some SQL statements will appear in more then one category.

What is ADDM report in Oracle?

The Automatic Database Diagnostic Monitor (ADDM) is a self-diagnostic engine built into Oracle Database. ADDM examines and analyzes data captured in the Automatic Workload Repository (AWR) to determine possible performance problems in Oracle Database. ADDM uses the DB time statistic to identify performance problems.

How do I make an AWR report?

Generating an AWR Compare Periods Report for the Local Database

  1. At the SQL prompt, enter: @$ORACLE_HOME/rdbms/admin/awrddrpt.sql.
  2. Specify whether you want an HTML or a text report: Enter value for report_type: html.
  3. Specify the number of days for which you want to list snapshot IDs in the first time period.

How do I know if my AWR snapshot is enabled?

Oracle uses the MMON background process to collect AWR statistics. You can disable this job by changing the parameter STATISTICS_LEVEL to BASIC then snapshots will not be taken automatically. You can re-enable this job by changing the parameter STATISTICS_LEVEL to TYPICAL then snapshots will be taken automatically.

How do I get an ADDM report?

The obvious place to start viewing ADDM reports is Enterprise Manager. The “Performance Analysis” section on the “Home” page is a list of the top five findings from the last ADDM analysis task. Specific reports can be produced by clicking on the “Advisor Central” link, then the “ADDM” link.

What is the use of AWR Report in Oracle?

Automatic Workload Repository report or AWR report collects, processes, and maintains performance statistics for problem detection and self-tuning purposes. This gathered data is stored both in memory and in the database and is displayed in both reports and views.

How do I find the AWR report in Oracle Enterprise Manager?

How to generate AWR Report from OEM Grid

  1. Choose the Database for which, AWR report to be generated.
  2. Choose Performance -> Snaphosts -> Automatic Workload Repository -> Run AWR Report.
  3. Select Beginning Snapshot, Go to time -> Click Go -> Click Ok.
  4. Select Ending Snapshot Go to time -> Click Go -> Click Ok.

What is SQL tuning?

SQL tuning is the iterative process of improving SQL statement performance to meet specific, measurable, and achievable goals. SQL tuning implies fixing problems in deployed applications. In contrast, application design sets the security and performance goals before deploying an application.

How do I manually take AWR snapshots?

Generate AWR Snapshot Manually

  1. Current available snapshots in database: select snap_id,BEGIN_INTERVAL_TIME,END_INTERVAL_TIME from dba_hist_snapshot where BEGIN_INTERVAL_TIME > systimestamp -1 order by BEGIN_INTERVAL_TIME desc;
  2. Generate a new snapshot: EXEC DBMS_WORKLOAD_REPOSITORY.
  3. Check the snapshots(whether new one is created or not )

What is AWR baseline in Oracle?

Internally, an AWR baselines is a range of snapshots that can be used to compare to other pairs of snapshots. The Oracle database server will exempt the snapshots assigned to a specific baseline from the automated purge routine.

How do I find my AWR retention period?

See how to periodically truncate the SQL tables from AWR. In this example the retention period is specified as 3 years (1,576,800 minutes) and the interval between each snapshot is 60 minutes. interval => 60, retention => 1576800);

How do I disable AWR?

Remove AWR collection job: disable(‘GATHER_STATS_JOB’). You can use OEM: Main Menu->Workload->Automatic Workload Repository, select the “Edit” button and then select the last radio group item labeled: Turn off Snapshot Collection, finally press OK.

How do I change the AWR retention period in Oracle?

Steps to Modify AWR Snapshot Interval

  1. STEP 1: Check the Database name and DBID. SQL> select name,dbid from v$database; NAME DBID ——— ———- ORADB
  2. STEP 2: Check the existing snapshot_interval time.
  3. STEP 3: Modify the existing snapshot interval.
  4. STEP 4: Check the modified snapshot interval.

What is retention period in Oracle?

The report service writes to the database every 1000 samples and retains the information for a defined amount of time. The following are the default retention periods: Daily samples (collected every 5 minutes): 5 days (repsvc. daily-samples-retention-days)

How do I take a manual AWR snapshot?

How do you set AWR retention period?

How do I check my AWR retention period?