find fix and_validate

Copyright © 2012, Oracle and/or its affiliates. All rights reserved. 1

Maximize your Database Performance Find, Fix and Validate

Jesús Leonardo Robles DB & O Business Development Manager

Valentín Leonard Tabacaru Presales Technology Consultant


Agenda

Database Performance Analysis

– Challenges and Solutions

1.- Find

2.- Fix

3.- Validate

Resources


Database Performance Analysis Challenges

•Reported by end users

•Discovered by daily checks

•Reactive to end-users

Find?

•Relate symptom to possible cause

•Relate possible cause to probable metric

•Implement change

Fix? •Did it work?

•End-user feedback?

•Run reports on metric

Validate?

•Will it occur again?

•Custom script to watch for the metric

•Complex alerting and notification

Track?

1

2

3

4


• For problem diagnosis use ADDM, EM Performance

• ADDM reveals significant problems including problematic SQL details and recommendations improve to performance

• ADDM family – Compare Period, Real-Time ADDM

1 – Find: Diagnostics


Boost Administrator Productivity

Eliminate Performance Bottlenecks

Lower IT Management Costs

Deliver Higher Quality of Service

Automatic Performance Diagnostics Maximize Performance With Self-Managing Database

• Sustain maximum performance with self-managing database

• Top-down analysis using Automatic Workload Repository snapshots

• Real-time performance analysis with Automatic Database Diagnostic Monitor

• Resolve performance issues faster with drill-down root-cause analysis

• Classification tree based on Oracle performance tuning expertise

• Performance expert; now a RAC specialist too in Oracle Database 11g

Automatic Workload

Repository Snapshots

Performance &

Management

Advisors

High

Load

SQL

RAC

Issues

IO / CPU

Issues

Self-Diagnostic

Engine


Performance Issues Automatically Diagnosed by ADDM

Top SQL I/O Issues

Parsing Configuration

Issues

Application Usage

Excessive Logon/Logoff

Undersized Memory

Hot Blocks and Objects

RAC Service Issues

Locks & ITL contention

Checkpoint causes

PL/SQL, Java Time


Real-Time ADDM—Architecture

• Makes a lightweight connection without acquiring additional locks and

resources, bypassing the SQL layer through the agent

• Also attempts to initiate standard JDBC connection

• Data returned by either connection is analyzed by Real-Time ADDM

EM Agent

JDBC Connection

Diagnostic Connection

ADDM

Analysis Database

Resource Constraints

Hangs

Memory Issues

Resource Limits Reached

Deadlocks

Top Issues Identified by

Real-Time ADDM


Real-Time ADDM


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 Snapshot

Period 1

AWR Snapshot

Period 2 Analysis Report Compare

Period ADDM

SQL Commonality

Regressed SQL

I/O Bound

Undersized SGA


Compare Period ADDM: Method

• Identify what changed

• DB configurations, workload changes

• Quantify performance differences

• Uses DB Time as basis for measuring performance

• Identify root cause

• Correlate performance differences with changes

Did the Buffer cache get smaller?

Why is there 10% new SQL?

Why Top SQL increased by 45%?

Read I/O are up by 55%, why?

Did a buffer cache reduction

cause a read I/O increase?


Compare Period – 3 Modes

One snapshot offset

System moving window

Customized period


Compare Period: Report


Active Session History (ASH)

All ‘Active’ sessions captured every second

• Foregrounds and backgrounds are sampled

• Active foregrounds contribute to DB Time

In-memory: V$ACTIVE_SESSION_HISTORY

• Sampling interval = 1 second

On-disk: DBA_HIST_ACTIVE_SESS_HISTORY

• Sampling interval = 10 seconds

ASH is a system-wide record of database activity

• A FACT table with multiple dimensions that help diagnose performance issues


Drilling into Logical Dimensions

ASH

SQL

PL/SQL

Resource Usage

Session Identifiers

Session Attributes

SQL

SQL ID

Plan Hash

Operation

OpCode

PL/SQL

PL/SQL

Top Level PL/SQL

Resources

Wait Class

Wait Event

Object

Blocking Session

Identifiers

Instance

Services

User Session

Parallel Process

Program

Session Type

Attributes

Cons. Group

Module

Action

Client

Trans. ID


ASH Analytics

Flexible Time Picker

Flexible Activity Chart

Flexible Top Chart Flexible Top Chart


• Seamless integration between Find and Fix

• In-depth analysis and recommendation of the fix

• Gather statistics for this example…

• How would we validate this changes?

2 – Fix: Tuning


SQL Problems

Bind-sensitive SQL with bind peeking

Literal usage

CURSOR SHARING

Cursor Sharing

Issues

Hardware resource crunch

Contention (row lock contention, block update contention)

Data fragmentation

Resource &

Contention

Issues

RESOURCES

Stale/Missing statistics

Incomplete statistics

Improper optimizer configuration

Upgraded Database: new optimizer

Changing statistics

Rapidly changing data

STATISTICS

Optimizer

Statistics Issues

Missing access structures

Poorly written SQL statements Application

Issues

APPLICATIONS

Not parallelized (no scaling to large data)

Improperly parallelized (partially parallelized, skews) Parallelism

Issues

PARALLELISM


SQL Tuning Advisor

SQL Tuning Advisor

Identifies alternate execution plans using

real-time and historical performance data

Recommends parallel profile if it will improve SQL performance significantly (2x or more)

SQL Profiling

Statistics Analysis

Access Path Analysis

SQL Restructure Analysis

Alternative Plan Analysis

Parallel Query Analysis

Automatic Tuning Optimizer

Administrator

SQL Tuning

Recommendations

Gather Missing or Stale Statistics

Create a SQL Profile

Add Missing Access Structures

Modify SQL Constructs

Adopt Alternative

Execution Plan

Create Parallel SQL Profile

SQL Tuning Advisor


Application Tuning Automatic SQL Tuning

Automatic SQL Tuning

•Captures high-load SQL

•Tunes SQL using SQL Profiles

•Implements improved SQL plans (optional)

Performance benefit of advice

provided

SQL Profiling tunes execution

plan without changing SQL

text

Enables transparent tuning for packaged

applications

Applications

High-Load

Packaged Apps + SQL Profile

Customizable Apps + SQL Advice

Customizable Apps + Indexes & MVs + Partitions

Tuned SQL

Automatic Tuning Optimizer


SQL Access Advisor

Automatic Tuning

Optimizer

SQL Cache

SQL Tuning

sets SQL Access Advisor

Indexes

Materialized Views

Materialized Views

Logs

Partitioned Objects

SQL Access Advisor

• Capture SQL Workload from multiple sources

Set filters on the Workload

SQL Access Recommendations


Real-Time SQL Monitoring Looking Inside SQL Execution

Guides tuning efforts Automatically

monitors

long running SQL

Enabled

out-of-the-box

with no performance impact

Monitors

SQL execution

Exposes monitoring statistics

Global execution level

Plan operation level

Parallel Execution level


SQL Monitoring Details Expensive Hash Join


Real-Time PL/SQL Monitoring

PL/SQL execution no longer a “black box”

•Answers questions like “why did my DBMS_STATS job take twice as long this time?”

Shows global (PL/SQL) and SQL level statistics

Each SQL called by PL/SQL recursively

monitored

Drill-down to slow SQL for diagnosing

unexpected PL/SQL behavior


Performance Diagnostics Active Reports

Interactive reports for

off-line analysis

Drill-downs for detailed analysis

Can be emailed

for analysis

Does not require Oracle Enterprise

Manager installation


D E M O N S T R A T I O N

Automatic SQL Tuning



Monitoring SQL Statements


• End-to-end SPA workflow using Optimizer Statistics

• Seamless integration from Find to Fix to Validate to Implement with confidence

• No more guesswork

3 – Validate: SPA


Real Application Testing SQL Performance Analyzer (SPA)

SQL Workload

STS

SQL Plans + Run-time Stats

Pre-Change Trial

SQL Plans + Run-time Stats

Post-Change Trial

Compare SQL

Performance Analysis Report

• Test and predict impact of system changes on SQL query performance

• Analyze performance changes for improvements and regressions

• Comprehensive performance analysis and reporting

• Re-execute SQL queries in the given environment

• End-to-end solution: STS, SQL Plan Baselines, and SQL Tuning Advisor


SPA Analysis Report Example

4

1

3 2

5


SPA Report Regressed SQL Statements


Usage Scenario: Evaluating Changes On Production


+Parameter

Change

Fix Regression thru

SPM

+Add

indexes

Using SPA For Changes in Production: Example

Fix Regression

SQL Profile

Prod

+SQL

Profile

+New Stats

Change

+Partitioning

+Validate

Tuning

Parameter change

was bad in this case

And so on…

+Index

Unusable

• Bubble following the arrow indicates the

delta change on Production

• SPA is used for testing every change


When to use SPA?

• Optimizer Statistics

• Database parameter changes

• Database schema changes (e.g., add/drop indexes)

• Implementation of tuning recommendations

• I/O subsystem changes (e.g., ASM, Database Machine)

• For consolidation (schema, CDB/PDB)

• On test, standby, and production environments

• Extended to home-grown scripts, application specific database changes, third-party testing tools using STS compare analysis

• Supports most applications - EBS, SAP, Siebel, home-grown, etc

SPA Provides Broad Testing Coverage

• My Oracle Support (MOS) Note: 560977.1

• 9.2/10.1 10.2 or 11g or 12 releases

• 10.2.0.x 10.2.0.y or 11g or 12 releases

SPA Provides Testing in Various Database Releases



SQL Access Advisor & SQL Performance Analyzer


Advanced Databases Performance Analysis Solution

• Built-in, self-diagnostics engine: Automatic Database Diagnostics Monitor (ADDM) (Diagnostics Pack)

Find

• Automates complex and time consuming task of application tuning (Tuning Pack)

Fix • Validates tuning and “what-if” activities (Real Application Testing)

Validate

• Extend EM out-of-box metrics - Can be defined for any target type, including applications (Metric Extensions)

Track


Resources

Oracle Enterprise Manager 12c:

http://www.oracle.com/us/products/enterprise-manager

Oracle Enterprise Manager 12c Database Management

http://www.oracle.com/technetwork/oem/db-mgmt

Database Manageability and Real Application Testing:

http://www.oracle.com/technetwork/database/manageability

Oracle Enterprise Manager on Beehive Online

Downloadable Technical Assets

[email protected] mailing list for support








http://www.oracle.com/technetwork/database/manageability

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