DAT335SQL Server 2000 Tips and Tricks: DBAs and Developers

Kimberly L. Tripp

Solid Quality Learning – SolidQualityLearning.com Email: Kimberly@SolidQualityLearning.com

SYSolutions, Inc. – SQLSkills.comEmail: Kimberly@SQLSkills.com

Introduction

Kimberly L. Tripp, SQL Server MVP

Principal Mentor, Solid Quality Learning* In-depth, high quality training around the world!

www.SolidQualityLearning.com

Content Manager for www.SQLSkills.com

Writer/Editor for TSQL Solutions/SQL Magwww.tsqlsolutions.com and www.sqlmag.com

Consultant/Trainer/Speaker

Coauthor for MSPress title: SQL Server 2000 High Availability

Presenter/Technical Manager for SQL Server 2000 High Availability Overview DVD

Very approachable. Please ask me questions!

Overview

Saving Production Data

Case Sensitive Searching

Creating Cool Constraints

All About Raiserror

Minimizing Transactional Code

VLDB Backup Best Practices – File/Filegroup Backup/Restore

Saving Production Data from Production DBAs

Data Disaster Issues

Schemabinding

Create SCHEMABOUND Views

Data Disaster Issues

Unexpected UPDATEs/DELETEsMinimize User’s permissions/direct access to base tables

Use stored procedures for consistency/integrity

Unexpected Table DropForeign Keys – protect a table from being dropped ONLY when other tables REFERENCE it… What about a Sales type of table?

CustomerIDSalesPersonIDProductID

SalesCustomerID

Customers

EmployeeID

Employees

ProductID

Products

@$#!&?!?

DROP TABLE Sales

Schemabinding

Solid Dependency Chains – Used to more permanently associate objects

All Objects on which a schemabound object is bound – must also be bound

All Objects must be referenced using two-part naming

Must explicitly name columns in object (no *)

No objects (or columns in definition of bound object) can be modified or dropped unless the object or schemabinding are removed!

CustomerIDSalesPersonIDProductID

Sales DROP TABLE Sales

Server: Msg 3729, Level 16, State 1, Line 1Cannot DROP TABLE 'Sales' because it is being referenced by…

Create SCHEMABOUND Views

Use WITH SCHEMABINDING in View DefinitionCREATE VIEW Sales_PreventTableDropView

WITH SCHEMABINDING AS

SELECT SalesID FROM dbo.Sales

Create Views on All objects you want to protect

Review TSQL Tutor Quick Tip, InstantDoc ID# 22073 for code to automate the creation!

www.TSQLSolutions.com or www.SQLMag.com

Case Sensitive Searching

Sort Order Concepts

Sort Order Options

Case Sensitive Searching

Sort Order Options

To see the list of collationsSELECT * FROM ::fn_helpcollations()

To see the server's settingsp_helpsort

To see the database's settingsp_helpdb dbname

To see the table's setting (for each column)sp_help tname

For more information, check out these BOL topics: COLLATE

"Specifying Collations"

Sort Order Concepts

May be changed at any point in chain

Different options offer different gains – most in language sorting, some in performance

Can assign on the fly for just a single query – or within a view for subsequent use

Can index the view for speedFull benefits of Indexed Views in Enterprise Edition only, see the whitepaper (listed in resources) for specific details.

Windows Install

SQL Server Install

Database Creation

Table Creation

Query Usage

I n h e r i t e d

} Use COLLATE option to change

Case Sensitive Searching

CREATE VIEW AuthorsLastNameCaseSensitiveAS SELECT au_lname COLLATE Latin1_General_CS_AS_KS_WS AS LastName FROM authorsgo

-- Select from the ViewSELECT * FROM AuthorsLastNameCaseSensitive WHERE LastName= 'ringer' -- 0 Rows

SELECT * FROM AuthorsLastNameCaseSensitive WHERE LastName= 'Ringer' -- 2 Rows!!!

Performance will NOT be good on large data sets. Consider creating an index on the AuthorsLastNameCaseSensitive View IF BOTH case-sensitive and case-insensitive searching is a common requirement for this table. See the Whitepaper: Improving Performance with Microsoft SQL Server 2000 Indexed Views.

Creating Cool Constraints

DEFAULT Constraints

CHECK Constraints

DO NOT USE WITH NOCHECK

DEFAULT Constraints

Need to adhere to CHECK constraints, if one exists

Must be compatible with column datatype

Can use system or user-defined functions!

InsertedBy varchar(60) NOT NULL

CONSTRAINT EmployeeInsertedByDflt

DEFAULT host_name() + '\' + suser_sname() + '\' + user_name()

RoadRunnerKT\domain\kimberly\kim

RoadRunnerKT\sa\dbo

Check Constraints (optimizer)All data will be checked on INSERT/UPDATE

PatternCHECK (Phone LIKE ‘(___) ___-____’)

*Range*CHECK (Salary < 750000)The only operators supported for increased performance gains are: BETWEEN, AND, OR, <, <=, >, >=, =. Others are supported for data integrity purposes only.

ListCHECK (Country Code IN (‘US’, ‘AU’, ‘GB’, ‘FR’))

Added during CREATE TABLE

Add later using ALTER TABLEBut what about the existing data?

DO NOT USE WITH NOCHECK

ALTER TABLE with CHECK – all existing data is checked and verified

ALTER TABLE with NOCHECK – speeds up the creation BUT there are no performance gains for later use of the constraint

ScenarioCharge Table 1.6 Million Rows

Constraint added with NOCHECK (ChargeAmt < 5000)

SELECT * FROM Charge WHERE ChargeAmt > 6000-- yields 9305 I/O

Constraint added with CHECK (ChargeAmt < 5000)

SELECT * FROM Charge WHERE ChargeAmt > 6000-- yields 0 I/O

All About RAISERROR

RAISERROR Syntax Reviewed

Parameterized Messages

RAISERROR Syntax Reviewed

RAISERROR(Error, Severity, State [, VariableList]WITH LOG

ErrorString – can be a parameterized or fixed string of up to 400 characters. When parameterized the variables need to follow using VariableList

Number System messages < 50000

50000 = default number for string messages

User defined messages > 50000, added with sp_addmessage

VariableList – Error string must follow a specific format using placeholders for variables. Variables can follow two formats – by position or by number

Examples coming up!

RAISERROR Syntax ReviewedRAISERROR(Error, Severity, State [, VariableList]) WITH

LOGSeverity 1-9

Error number in black with error message @@ERROR is NOT set

Severity 10 ONLY the error message is returned, no error number is returned@@ERROR is NOT set

Severity 11-14 Error number in red with error message @@ERROR is set

Severity 15 Error number in red with error message @@ERROR is set

Severity 16 Error number in red with error message @@ERROR is set

For more information, see the BOL topic“Error Message Severity Levels”

Informational

Warning

Error

When Logged to the Event Viewer

Application Log

RAISERROR Syntax Reviewed

RAISERROR(Error, Severity, State [, VariableList]WITH LOG

StateUsually avoided by using 1

Virtually no use…except one!

Using osql.exe and a state of 127 you can control the termination of a complex script before it executes in the wrong database!

IF DATABASEPROPERTYEX('DBName', 'COLLATION') IS NULL

BEGIN

RAISERROR ('Error Message.', 16, 127)

END

Parameterized Messagesexec sp_addmessage @msgnum = 900001, @severity = 16,

@msgtext = 'Value %s is invalid. Procedure %s expected a value of TRUE or FALSE for parameter %s. The default is %s.', @lang = 'US_English', @with_log = 'FALSE'

go

exec sp_addmessage @msgnum = 900001, @severity = 16, @msgtext = 'La valeur %s est inadmissible. Le procédé %s s''est attendu à une valeur de VRAI ou de FAUX pour le paramètre %s. Le défaut est %s.'

-- translation provided by www.babblefish.com , @lang = 'French', @with_log = 'FALSE'

go

RAISERROR(900001, 16, 1, ‘string’, ‘string’,‘string’,‘string’) WITH LOG

Minimize Transactional Code

UPDATE Syntax Reviewed

Common Transaction Mistakes

Using an UPDATE to Minimize Transactional Code

Real World Changes for Better Performance

UPDATE Syntax ReviewedDECLARE @id varchar(10)SELECT @id = (SELECT MIN(title_id) FROM dbo.titles

WHERE type = 'business')UPDATE titles SET type = 'MinTest', WHERE @id = title_id --Min may have changedSELECT @idgoDECLARE @id varchar(10)UPDATE titles SET type = 'MinTest', @id = title_id WHERE title_id = (SELECT MIN(title_id) FROM

dbo.titlesWHERE type = 'business')

SELECT @id

Common Transaction Mistakes

Worst Scenario (Data Integrity Problems)BEGIN TRAN

SELECT data to analyze before update

IF data is OK then UPDATE (data may have changed)

Reselect data to return to client

COMMIT TRAN

Better Scenario (No Data Integrity Issues)BEGIN TRAN

UPDATE data right away

Reselect data and Verify UPDATE

Return Data to client

COMMIT TRAN

Updates to Minimize Code

Best Case Scenario No Data Integrity Issues

Best Performance

BEGIN TRANUPDATE data and assign variable for Verify

Verify UPDATE

Return Data to client

COMMIT TRAN

Sometimes you can even get rid of the BEGIN TRAN and COMMIT TRAN!

Real World ChangesBEGIN TRAN

EXEC sp_executesql N'UPDATE dbo.table with (ROWLOCK, UPDLOCK) SET Col1 = Col1 + @U1 WHERE Type = @U2 SELECT Col1 FROM dbo.table WHERE Type =

@U3', N'@U1 int,@U2 int, @U3 int', @U1=1,@U2=0,@U3=0

COMMIT TRAN

-- Was changed to:

EXEC sp_executesql N'UPDATE dbo.table WITH (ROWLOCK, UPDLOCK)

SET @Col1 = Col1 = Col1 + @U1 WHERE Type = @U2‘

, N'@U1 int,@U2 int‘, @U1=1,@U2=0

-- But sp_executesql is not necessary...

UPDATE dbo.tableSET @Col1 = Col1 = Col1 + @U1WHERE Type = @U2

VLDB Backup Best Practices

File/Filegroup Backup Strategies

Case Study/Self Paced Example

Gathering Backup History

File/Filegroup Backup Strategies

Require Transaction Log backups for Restore

Require FULL and/or Bulk Logged Recovery Model

Do NOT Require a FULL Backup to have been performed – ever!

Can BACKUP Files individually – not restricted to backup all files in a Filegroup (this was a change from SQL Server 7.0)

Add Improved Restore Capabilities (less time) at the expense of some Administrative Complexity

Case Study

Primary

File1

File2

File3

Log

time

TLOG

TLOG

TLOG

TLOG

TLOG

TLOG

1 2 3 4 5 6 7 8 9 10 11X

FILE

FILEF

ILEGROUP

DIFF

FG

DIFF

FG

Step 1 – Determine how to get the structure of the database created. Tip – need the Primary and all other FULL file/filegroup backups. Backups 7 and 3.

Step 2 – Bring the file/filegroups up to the minute as fast as possible. Tip – find the latest differentials. Backup 9.

Step 3 – Apply the Transaction Logs that will make this database consistent. Tip – Look for the oldest FULL file/filegroup or differential and then check for the min LSN. Backups – 6?, 8, 10, and 11.

DB

CREATE

fileg

roup

Demo

Gathering Backup HistoryFrom Devices – LOAD HEADERONLY

From MSDB, if the information existsSELECT Backup_Start_Date,

[Name],

[Description],

First_LSN,

Last_LSN,

Backup_Finish_Date,

* -- OR Just *

FROM msdb.dbo.backupset AS s

JOIN msdb.dbo.backupmediafamily AS m

ON s.media_set_id = m.media_set_id

WHERE database_name = 'PubsTest'

ORDER BY 1 ASC

Must find the Minimum Effective LSN

* Take the oldest of the last few files or filegroups that have been restored and see what the FIRST_LSN is –

that’s your minimum effective LSN.

* Next find the FIRST log that includes this LSN.

Review

Saving Production Data

Case Sensitive Searching

Creating Cool Constraints

All About Raiserror

Minimizing Transactional Code

VLDB Backup Best Practices – File/Filegroup Backup/Restore

DAT 335 – SQL Server Tips and Tricks for DBAs and DevelopersTuesday, 1 July 2003, 15:15-16:30DBA 324 – Designing for Performance: Structures, Partitioning, Views and ConstraintsWednesday, 2 July 2003, 08:30-09:45DBA 328 – Designing for Performance: Optimization with IndexesWednesday, 2 July 2003, 16:45-18:00DBA 322 – Optimizing Stored Procedure Performance in SQL Server 2000Thursday, 3 July 2003, 08:30-09:45

Other Sessions…Other Sessions…

Articles in TSQLSolutions at www.tsqlsolutions.com (FREE, just register)

All About Raiserror, InstantDoc ID#22980

Saving Production Data from Production DBAs, InstantDoc ID#22073

Articles in SQL Server Magazine, Sept 2002:Before Disaster Strikes, InstantDoc ID#25915

Log Backups Paused for Good Reason, InstantDoc ID#26032

Restoring After Isolated Disk Failure, InstantDoc #26067

Filegroup Usage for VLDBs, InstantDoc ID#26031

Search www.sqlmag.com and www.tsqlsolutions.com for additional articles

Articles…Articles…

Inside Microsoft SQL Server 2000, Kalen Delaney, MS Press, ISBN: 0735609985 http://www.insidesqlserver.com/

Whitepaper: Index Tuning Wizard for Microsoft SQL Server 2000, http://msdn.microsoft.com/library/en-us/dnsql2k/html/itwforsql.asp?frame=true

Whitepaper: Improving Performance with Microsoft SQL Server 2000 Indexed Views, http://msdn.microsoft.com/library/en-us/dnsql2k/html/indexedviews1.asp?frame=true

Resources…Resources…

Community Resources

Community Resourceshttp://www.microsoft.com/communities/default.mspx

Most Valuable Professional (MVP)http://www.mvp.support.microsoft.com/

NewsgroupsConverse online with Microsoft Newsgroups, including Worldwidehttp://www.microsoft.com/communities/newsgroups/default.mspx

User GroupsMeet and learn with your peershttp://www.microsoft.com/communities/usergroups/default.mspx

Suggested Reading And Resources

The tools you need to put technology to work!The tools you need to put technology to work!

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Microsoft® SQL Server™ 2000 Microsoft® SQL Server™ 2000 High Availability: 0-7356-1920-4High Availability: 0-7356-1920-4

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Kimberly L. Tripp Principal Mentor, Solid Quality Learning

Website: www.SolidQualityLearning.com

Email: Kimberly@SolidQualityLearning.com

President, SYSolutions, Inc.Website: www.SQLSkills.com

Email: Kimberly@SQLSkills.com

Thank You!Thank You!

© 2003 Microsoft Corporation. All rights reserved.© 2003 Microsoft Corporation. All rights reserved.This presentation is for informational purposes only. MICROSOFT MAKES NO WARRANTIES, EXPRESS OR IMPLIED, IN THIS SUMMARY.This presentation is for informational purposes only. MICROSOFT MAKES NO WARRANTIES, EXPRESS OR IMPLIED, IN THIS SUMMARY.