Database Snapshots

Said Salomontimelord@timelordshangout.com

Who am I?

I has over 25 year experience as an Information Technology Professional. He has a vast array of abilities in the field in the areas of Network, Desktop Support, DBA, Staff Project Management, Application Software Development, Business Analysis and Quality Assurance. I have Microsoft certifications as a MCTS, MCPS, and MCNPS, and multiple certifications from the Insurance Institute of America. Current Said is a DBA at Unitrin Direct Insurance.

Philadelphia SQL Server User Group (PSSUG)Up coming events

Date Topics Location

10/13/2010 at 5:30PM

SSRS R2Parallel Data Warehouse

Microsoft Malvern Office

10/18/2010 at 6:00PM

System Tables part 1 Live Meeting event

10/26/2010 at 5:30PM

Dyn Config PackagesSQL 2008 R2 Overview

Haddon Heights Library(South Jersey)

11/10/2010 at 5:30PM

TBA Microsoft Malvern Office

11/08/2010 - 11/12/2010

PASS Summit Seattle, WA

11/15/2010 at 6:00PM

System Tables part 2 Live Meeting event

12/08/2010 at 5:30PM

TBA Microsoft Malvern Office

March 2011 Philly SQL Saturday TBA

Specializing in Database and Business Intelligence topics for Philly and SJ

For More Info: http://www.pssug.org

Agenda

What is Database Snapshot Why use Database Snapshot What can be done with Database

Snapshot How does a Database Snapshot work Review basic T-SQL syntax Demo Q&A

What is Database Snapshot? Microsoft – “A database snapshot is a

read-only, static view of a database, called the source database. In Microsoft SQL Server 2005 and later versions, you must use Transact-SQL statements for creating, reverting to, and deleting a database snapshot. However, you can use SQL Server Management Studio to view existing database snapshots.”

What is it???

A database snapshot is a point in time read only snapshot. It looks like a copy of the database but normally takes up less than 10% space.

How Database snapshots work

When to use a Database Snapshot

Restrictions on Database Snapshots

Enterprise only can not backup a snapshot The source database cannot be

dropped, detached, or restored. Performance is reduced Snapshots of the model, master,

and tempdb databases are prohibited

Create Database Snapshot CREATE DATABASE

ssAdventureWorks_MySnap ON ( NAME = AdventureWorks_Data, FILENAME = 'C:\Program Files\Microsoft SQL Server\MSSQL.1\MSSQL\Data\AdventureWorks_MySnap.ss' ) AS SNAPSHOT OF AdventureWorks; GO

Select from Database Snapshot

SELECT * FROM [ssAdventureWorks_MySnap].

[HumanResources].[Employee]

Restoring from Database Snapshot

RESTORE DATABASE AdventureWorks from DATABASE_SNAPSHOT = 'ssAdventureWorks_MySnap'; GO

Dropping Database Snapshot

DROP DATABASE [ssAdventureWorks_MySnap]

Demo

Demo

Snapshot Creation Time

100 500 1000 15000

500

1000

1500

2000

2500

Database Snapshot Creation Time with Varying Workload

User Load (Number of active user connections)

Data

base s

napshot

cre

ati

on t

ime (

seconds)

Multiple Snapshots

1 2 3 4 50

500

1000

1500

2000

2500

3000

3500

4000

Creating Multiple Successive Database Snapshots

500 Users 1000 Users 1500 Users

Number of Database Snapshots

Data

base s

napshot

cre

ati

on t

ime (

sec)

Snapshot Response Time

01

23

45

0

2

4

6

8

10

12

Impact of Multiple Database Snapshots on Transaction Response Time

Transaction 1 Transaction 2 Transaction 3 Transaction 4 Transaction 5

Number of Existing Database Snapshots

Avera

ge R

esponse T

ime (

sec)

Snapshot Index Creation

NonClustered Index Clustered Index NonClustered Index Clustered Index0 500

0

1000

2000

3000

4000

5000

6000

7000

8000

Impact of Database Snapshot creation on Index Creation

With No DB Snapshot With 1 DB Snapshot

User Load (Number of Active User Sessions)

Index C

reati

on T

ime (

seconds)

Resources

Microsoft http://msdn.microsoft.com/en-us/library/ms175158.aspx

Limts: http://msdn.microsoft.com/en-us/library/ms189940.aspx

Performance: http://sqlcat.com/whitepapers/archive/2008/02/11/database-snapshot-performance-considerations-under-i-o-intensive-workloads.aspx

http://www.timelordshangout.com

Philadelphia SQL Server User Group (PSSUG)Up coming events

Date Topics Location

10/13/2010 at 5:30PM

SSRS R2Parallel Data Warehouse

Microsoft Malvern Office

10/18/2010 at 6:00PM

System Tables part 1 Live Meeting event

10/26/2010 at 5:30PM

Dyn Config PackagesSQL 2008 R2 Overview

Haddon Heights Library(South Jersey)

11/10/2010 at 5:30PM

TBA Microsoft Malvern Office

11/08/2010 - 11/12/2010

PASS Summit Seattle, WA

11/15/2010 at 6:00PM

System Tables part 2 Live Meeting event

12/08/2010 at 5:30PM

TBA Microsoft Malvern Office

March 2011 Philly SQL Saturday TBA

Specializing in Database and Business Intelligence topics for Philly and SJ

For More Info: http://www.pssug.org