maximize db performance top10 tips final

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Copyright 2012, Oracle and/or its affiliates. All rights reserved. Insert Information Protection Policy Classification from Slide 131

Maximize Oracle Database Performance

with Oracle Enterprise Manager 12c:Top 10 Tips & Tricks

Scott McNeil

Principal Product Director, Oracle

Deba ChatterjeePrincipal Product Manager, Oracle


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Top 10 Common Problems:

1. Performance was fine yesterday, today my application is really slow?

2. My database has hung? I do not want to bounce it.

3. I enabled parallel query, yet this query is taking to long. Why?4. My simple query takes so long. Whats wrong with the database?

5. Detecting runaway queries with metric extensions?

6. What happened last night, the batch job took twice the time to finish?

7. The SQL Response Metric crossed the warning threshold. What is wrong?

8. We just went live after a DB change and now performance has regressed, 9. We are going through a schema consolidation, how can I ensure one sessi

away with all my system resources?

10. The new BI system has very aggressive SLAs defined. How can we ensureperformance across the system?


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Copyright 2012, Oracle and/or its affiliates. All rights reserved.3

3 Types ofPerformanceManagement

ReactivePerformance

Management

ProactivePerformance

Management

P

M


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5/56Copyright 2012, Oracle and/or its affiliates. All rights reserved.5

Reactive Performance Management

Comparing PerformanceAcross Two Time Periods

Database Hang Analysis

SQL Performance AnalysisI

SQL Performance Analysis -II


6/56Copyright 2012, Oracle and/or its affiliates. All rights reserved.6

Comparing Performance AcrossTwo Periods

Inconsistent Performance

Over utilization of system resources

High load ad hoc query consuming resources Change in execution plan of query

Parallel execution downgrade

Performance was fine yesterday, today my

application is really slow?


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Tip: Compare Period ADDM

Full ADDM analysis across two AWR snapshot periods

Detects causes, measure effects, then correlates them

Causes: workload changes, configuration changes

Effects: regressed SQL, reach resource limits (CPU, I/O, memory, interconnect)

Makes actionable recommendations along with quantified impact

AWR SnapshotPeriod 1

AWR SnapshotPeriod 2

Analysis ReportComparePeriod ADDM

S

R

I

U


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30% sm

10% new

Compare Period ADDM: Method

Identify what changed Configuration changes, workload

changes

Quantify performance differences

Uses DB Time as basis formeasuring performance

Identify root cause Correlate performance

differences with changes

Top SQL

Read I/O

Buffer cacaused


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Comparing Performance AcrossTwo Time Periods


SQL Performance Analysis I

SQL Performance Analysis II

CPe


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Database Hung state

Blocking Sessions

Memory allocation issues Library cache issues

Unresponsive Storage (ASM)

Interconnect problems

My database is hung? I do not want to

bounce it.


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Tip: Real-Time ADDMEM Agent

JDBC Connection

Diagnostic Connection

Database

ADDMAnalys

Uses a pre-established diagnostic connection for unresponsive sys

Initiates a standard JDBC connection for real-time analysis

Diagnostic connection collects data without holding latches or runn

First intelligent advisor to diagnose problems in real-time as they ohow sick the system is

Real-Time Analysis

Unresponsive DB


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Real-Time ADDM

Real-time analysis of hung or slow database systems Holistically identify global resource contentions and deadlocks Quantified performance impact Precise, actionable recommendations Provide cluster-wide analysis for RAC


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CPeri

ReA


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SQL Performance Analysis

I enabled parallel query, yet this query is takingso long. Can you take a look?

Parallel Downgrades

Uncontrolled parallel execution

Parallel Server availability

Object level settings

Session level settings


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Tip: Real-Time SQL MonitoringInsert Executed with Parallel Hint


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Real-Time SQL MonitoringParallel Tab

Parallel Coordinator busy for the entire duration!!


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Real-Time SQL MonitoringEnabled Parallel DML

Parallel Slaves busy for the entire duration!!!

SQL P f A l i


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SQL Performance Analysis

My simple query takes so long. Whats wrong

with the database?

SQL Performance Problems

Statistics

Resources Application issues

Parallelism

Initialization parameters


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Tip: Real-Time SQL MonitoringSQL with Count and Group By


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Real-Time SQL MonitoringSQL with Count and Group By


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Real-Time SQL MonitoringPGA Size Increased


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Mo





CPeri

ReA


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Proactive Performance Management

Dealing with run awayqueries

Understanding WorkloadProfile I

Understanding WorkloadProfile II


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Runaway Query

SQL that consumes too much CPU or executes too long BUGS: Need to find during Development and Testing conte

Real-time SQL Monitoring introduced in DB 11g

Monitors long-running and parallel query (PQ) SQL execut

Rich interactive user interface and Active Report

GV$SQL_MONITOR

Not really intended for user-written queries


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What are Oracle Enterprise Manager 12c Metric Ex

User extensions to EM target monitoring metrics

Replacement for EM 10/11 User Defined Metrics (UDM) First-class EM Metrics: Metric Group of Metric Columns

Multiple measure columns with alert threshold capability

Key column support, including key-specific thresholds

Supports SQL, OS, and JMX fetchlets

Whatever the target type already uses

Lifecycle support: Develop, Test, Deploy


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GV$SQL_MONITORquery

SQL_ID: key column

TotalCPUSecs

TotalElapsedSecs

Execute every 15-minutes(to not miss anything)

Set alert thresholds onCPU and Elapsed times

Design Metric Extension


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Find Metric Extensions


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Manage Metric Extensions


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Guided wizard makes iteasy

Well organized

Excellentexplanations

Develop and test onany database beforedeploying to production

Create Metric Extension


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P ti P f M t


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Run away queries

Understanding WorkloadProfile I

Understanding WorkloadProfile II

MExte

Understanding Workload Profile


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What happened last night, the batch job tooktwice the time to finish ?

We can look at AWR and ASH Data

Averaged out over the snapshot window

On-disk ASH Data

Sampled every 10 seconds

Very difficult to detect such issues in the past

Database Response Time AnalysisAW


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Database Response Time Analysis AW

AWR top 5 section

shows the Wait Classwhich contributes mostto DB wait time

Objects involved in TX rcontention can be identSegment Statistics secti

Foreground Wait Class secAWR to see distribution of Dover Waits classes

From AWR to ASH


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From AWR to ASH

ASH report for theperiod of increase

of Application waitswill show the samewaits as AWR

Can I get the App

Module which sufrom this type ofcontention ?

Extracting More Data From ASH


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Identify SQL statements and sessions impacted by waits Application Wait Class



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Get a list of blocking sessions and DB objects !



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Reactive Tracing of LongRunning Programs

Understanding WorkloadProfile - I

Understanding WorkloadProfile - II

DatOpe

CoAWR



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g

The SQL Response Metric crossed the warningthreshold. What is wrong?

Several factors can impact SQL Response time Increased or unusual load on system

Hardware issues

Runaway queries consuming system resources

Changes in execution plans

Missing or stale object statistics

Need a mechanism to quickly analyze in-memoryperformance data

Tip: Understanding Workload Profile


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Tip: Understanding Workload Profile

Graphical ASH report for advanced analysis

Provides visual filtering for recursive drill-downs

Select any time period for analysis

Analyze performance across many dimensions

Different visualizations: STree Map

Collaborate with others uReports



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Reactive Tracing of LongRunning Programs

Understanding WorkloadProfile - I

Understanding WorkloadProfile - II

DatOpe

CorAWR

AAna


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Preventive Performance Management


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Prevent Regression AfterUpgrade

Ensure Optimal ResourceAllocation

Prevent Performance IssuesDue to Application Changes

Case


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DATABASE MANAGEMENT187 Million Members$252 Million in Revenue800 Oracle Databases1,400 Applications

Preventiv

Challenge: LinkedIns ERP systems were being upgraded from

DB 10g to DB11g Presence of a large amount of custom code Limited time frame to complete the upgrade. Management concern about System performance Initial testing showed no major problems/concerns

A week before go-live several potentialshowstopper performance issues were noticed. Re-writing or tuning several pieces of code was not

feasible in a short window of time. Decision to use either SQL Profiles or Baselines to

regress to the DB10g plan in the interim

Using Oracle Enterprise Ma Used EM to regress back to thejob that calls the slow performin

Used SQL Tuning Advisor to drsession and identify the SQL ID

You can compare the explain pexplain plan in the same windo

Click through guided wizard to profile

DONE!!!

SQL Tuning Advisor


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Comprehensive SQL Tuning Recom

Gather Missing or StaleStatistics

Create a SQL Profile

Add Missing AccessStructures

Modify SQL Constructs

Adopt AlternativeExecution Plan (11.2)

Create Parallel SQLProfile (11.2)

SQL Profiling

Statistics Analysis

Access Path Analysis

SQL Restructure Analysis

Alternative Plan Analysis

Parallel Query Analysis

Automatic Tuning Optimizer

SQL TuningAdvisor

Analyzes statistics for accuracy Recommends SQL Profiles for transparent application tuning

Suggest access structures and alternate SQL to speed up query exe

Identifies alternative execution plans using real-time and historical pedata to recover from plan regression

Recommends appropriate degree of parallelism for best performance



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SQ

Ensure Optimal Resource Allocation


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We are going through a schema consolidation,how can I ensure one schema / user will not

run away with all my system resources?

Database resource manager directives preventa single user session to run away with allresources

Create a resource allocation strategy Allocate appropriate CPU and I/O (Exadata)

across consumer groups

Allocating Resources in the Database


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g

Gives maximum flexibility for each Consumer Group Allows any Consumer Group to consume all available Risky as one Consumer Group can run away with al

No ResourceAllocation

Ensures all Consumer Group get a specific share of t Allows any Consumer Group to consume any unused Kicks in at 100% resource utilization. Assumes that not all Consumer Group will use its allo

Specify a minimumallocation

Ensures all Consumer Group get a specific share of t Prevents a Consumer Group from taking more than t

assigned. May result in unused capacity

Specify a minimumand maximum

Tip: Setting up Resource Manager in Oracle Ent


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Manager

Extremely simple to manage resource plans using EnterprManager UI



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e e t e e o a ce a age e t




SQ

DB

Prevent Performance Issues Due toApplication Changes


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Application Changes

The new BI system has very aggressive SLAsdefined. How can we ensure consistentperformance across the system?

Code migration, new indices, objects can oftenimpact performance of the application

How do we validate the performance of criticalqueries before rolling out these changes ?

Validate


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Trial 1

01001011001010100100100100100100100100100100100010010101001001001001110010010010010010010000100100000101110010010101001001001010101001000100000101010010010101010011010100101010010010101001100101

Impact of Custom Code Migration

Use SPA Guided Workflow (recommended) or PL/SQL APIs

Create a SQL tuning set of the top X (20 or 30) queries

Establish first trial remotely using current state baseline

Make change Create the indexes or migrate custom code

Establish second trial remotely using the same SQL Tuning Set

Review SPA report and rollout or rollback changes.

Trial 2

Central SPA System Production

State 1

State 2

Tip: Take the Guess Work Out!


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Mamoqu

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SQ

D

FINAL Tip: Use Oracle Database Management TecSo You Can


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So You Can

Manage:

MORE databases

MOREapplications: OLTP, DW, OCS, iAS, SaaS, DBaaS MOREusers, larger databases

MOREmission-critical applications

Become:

MOREproactive and strategic

MORE important and valuableGet:

MORE sleep at night!

MORE weekends off!


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