Real World Tales - Oracle · High numbers of processes will cause outages Maximum connection count...

Real World Tales Realizing the Full Potential of Oracle Database On Premise and in The Cloud

Bob Carlin, Andrew Holdsworth, Graham Wood Real World Performance Group, Oracle RDBMS Dev October 27, 2015

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Program Agenda

Introduction

Connections

Cursor Management

1

2

3

4


Program Agenda

Introduction

Connections

Cursor Management

1

2

3

5


Real-World Performance Root Causes

The database is not being used as it was designed to be used

The application architecture/code design is sub-optimal

There is a sub optimal algorithm in the database

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Perception

DB Usage and Application Code

DB Internals

Focus in on exploring what is going on inside the database

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Reality

DB Usage and Application Code

DB Internals

Focus should be spent on how the database is being used

Where is the Performance Problem ?


This is a Dog

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This is a Dog on Premise This is a Dog in the Cloud

If Your Application is a Dog !


Program Agenda

Introduction

Connections

Cursor Management

1

2

3

9


85% OLTP Escalations coming into the Real World Performance Group are related to connection management

11


Connections: What We Hear

We want connections to grow as load increases

We never want the middle tier to have to wait for a connection to the database

We need to be ‘Web scale’

The database can’t handle the load

12


Demo Connections

13


Connections: Digging deeper

It’s fine most of the time

We sometimes see logon spikes

We have big response time variations as load increases

We see lots of concurrency waits when it’s bad

21


Connections: The Truth

Dynamic connection pools will cause logon storms

High numbers of processes will cause outages

Maximum connection count should be related to capacity i.e. cores

The middle tier is the most effective place to queue

22


Program Agenda

23

Introduction

Connections

Cursor Management

1

2

3


Cursor Management: What We Hear

We hire the brightest and best developers

Our development organization is highly agile

We shouldn’t need to train our developers to use Oracle

24


Demo Cursors

25


Cursor Management: Digging Deeper

Unable to get hardware busy

Lots of shared pool contention events

There is a security issue

Spending lots of CPU on parsing

27


Cursor Management: The Truth

Orders of magnitude of performance unrealized

Using bind variables protects you from SQL injection

Soft parses are not free

Untrained developers will not produce the most scalable Oracle applications

28


Summary

Architecture and build methods are critical for performance and reliablility

Aim for less than ten processes per CPU core

Static connection pools

Train your developers to use the product as it was designed to be used

29


Real-World Red Flags for OLTP

High numbers of connections

Application Servers regularly cycled

Killer scripts

30


Where to get more info

• Real-World Performance Engineers discussing and demonstrating performance issues, root causes and when to apply the correct techniques

– The Optimizer

– Core DB Performance

– Extreme OLTP

– Extreme DW

• http://www.oracle.com/goto/oll/rwp

11/4/2015

Real-World Performance Online Video Series

http://www.oracle.com/goto/oll/rwp

Real World Tales - Oracle · High numbers of processes will cause outages Maximum connection count...

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