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📄 Contents

  1. SQL Server Reference Guide
  2. Introduction
  3. SQL Server Reference Guide Overview
  4. Table of Contents
  5. Microsoft SQL Server Defined
  6. SQL Server Editions
  7. SQL Server Access
  8. Informit Articles and Sample Chapters
  9. Online Resources
  10. Microsoft SQL Server Features
  11. SQL Server Books Online
  12. Clustering Services
  13. Data Transformation Services (DTS) Overview
  14. Replication Services
  15. Database Mirroring
  16. Natural Language Processing (NLP)
  17. Analysis Services
  18. Microsot SQL Server Reporting Services
  19. XML Overview
  20. Notification Services for the DBA
  21. Full-Text Search
  22. SQL Server 2005 - Service Broker
  23. Using SQL Server as a Web Service
  24. SQL Server Encryption Options Overview
  25. SQL Server 2008 Overview
  26. SQL Server 2008 R2 Overview
  27. SQL Azure
  28. The Utility Control Point and Data Application Component, Part 1
  29. The Utility Control Point and Data Application Component, Part 2
  30. Microsoft SQL Server Administration
  31. The DBA Survival Guide: The 10 Minute SQL Server Overview
  32. Preparing (or Tuning) a Windows System for SQL Server, Part 1
  33. Preparing (or Tuning) a Windows System for SQL Server, Part 2
  34. Installing SQL Server
  35. Upgrading SQL Server
  36. SQL Server 2000 Management Tools
  37. SQL Server 2005 Management Tools
  38. SQL Server 2008 Management Tools
  39. SQL Azure Tools
  40. Automating Tasks with SQL Server Agent
  41. Run Operating System Commands in SQL Agent using PowerShell
  42. Automating Tasks Without SQL Server Agent
  43. Storage – SQL Server I/O
  44. Service Packs, Hotfixes and Cumulative Upgrades
  45. Tracking SQL Server Information with Error and Event Logs
  46. Change Management
  47. SQL Server Metadata, Part One
  48. SQL Server Meta-Data, Part Two
  49. Monitoring - SQL Server 2005 Dynamic Views and Functions
  50. Monitoring - Performance Monitor
  51. Unattended Performance Monitoring for SQL Server
  52. Monitoring - User-Defined Performance Counters
  53. Monitoring: SQL Server Activity Monitor
  54. SQL Server Instances
  55. DBCC Commands
  56. SQL Server and Mail
  57. Database Maintenance Checklist
  58. The Maintenance Wizard: SQL Server 2000 and Earlier
  59. The Maintenance Wizard: SQL Server 2005 (SP2) and Later
  60. The Web Assistant Wizard
  61. Creating Web Pages from SQL Server
  62. SQL Server Security
  63. Securing the SQL Server Platform, Part 1
  64. Securing the SQL Server Platform, Part 2
  65. SQL Server Security: Users and other Principals
  66. SQL Server Security – Roles
  67. SQL Server Security: Objects (Securables)
  68. Security: Using the Command Line
  69. SQL Server Security - Encrypting Connections
  70. SQL Server Security: Encrypting Data
  71. SQL Server Security Audit
  72. High Availability - SQL Server Clustering
  73. SQL Server Configuration, Part 1
  74. SQL Server Configuration, Part 2
  75. Database Configuration Options
  76. 32- vs 64-bit Computing for SQL Server
  77. SQL Server and Memory
  78. Performance Tuning: Introduction to Indexes
  79. Statistical Indexes
  80. Backup and Recovery
  81. Backup and Recovery Examples, Part One
  82. Backup and Recovery Examples, Part Two: Transferring Databases to Another System (Even Without Backups)
  83. SQL Profiler - Reverse Engineering An Application
  84. SQL Trace
  85. SQL Server Alerts
  86. Files and Filegroups
  87. Partitioning
  88. Full-Text Indexes
  89. Read-Only Data
  90. SQL Server Locks
  91. Monitoring Locking and Deadlocking
  92. Controlling Locks in SQL Server
  93. SQL Server Policy-Based Management, Part One
  94. SQL Server Policy-Based Management, Part Two
  95. SQL Server Policy-Based Management, Part Three
  96. Microsoft SQL Server Programming
  97. An Outline for Development
  98. Database
  99. Database Services
  100. Database Objects: Databases
  101. Database Objects: Tables
  102. Database Objects: Table Relationships
  103. Database Objects: Keys
  104. Database Objects: Constraints
  105. Database Objects: Data Types
  106. Database Objects: Views
  107. Database Objects: Stored Procedures
  108. Database Objects: Indexes
  109. Database Objects: User Defined Functions
  110. Database Objects: Triggers
  111. Database Design: Requirements, Entities, and Attributes
  112. Business Process Model Notation (BPMN) and the Data Professional
  113. Business Questions for Database Design, Part One
  114. Business Questions for Database Design, Part Two
  115. Database Design: Finalizing Requirements and Defining Relationships
  116. Database Design: Creating an Entity Relationship Diagram
  117. Database Design: The Logical ERD
  118. Database Design: Adjusting The Model
  119. Database Design: Normalizing the Model
  120. Creating The Physical Model
  121. Database Design: Changing Attributes to Columns
  122. Database Design: Creating The Physical Database
  123. Database Design Example: Curriculum Vitae
  124. NULLs
  125. The SQL Server Sample Databases
  126. The SQL Server Sample Databases: pubs
  127. The SQL Server Sample Databases: NorthWind
  128. The SQL Server Sample Databases: AdventureWorks
  129. The SQL Server Sample Databases: Adventureworks Derivatives
  130. UniversalDB: The Demo and Testing Database, Part 1
  131. UniversalDB: The Demo and Testing Database, Part 2
  132. UniversalDB: The Demo and Testing Database, Part 3
  133. UniversalDB: The Demo and Testing Database, Part 4
  134. Getting Started with Transact-SQL
  135. Transact-SQL: Data Definition Language (DDL) Basics
  136. Transact-SQL: Limiting Results
  137. Transact-SQL: More Operators
  138. Transact-SQL: Ordering and Aggregating Data
  139. Transact-SQL: Subqueries
  140. Transact-SQL: Joins
  141. Transact-SQL: Complex Joins - Building a View with Multiple JOINs
  142. Transact-SQL: Inserts, Updates, and Deletes
  143. An Introduction to the CLR in SQL Server 2005
  144. Design Elements Part 1: Programming Flow Overview, Code Format and Commenting your Code
  145. Design Elements Part 2: Controlling SQL's Scope
  146. Design Elements Part 3: Error Handling
  147. Design Elements Part 4: Variables
  148. Design Elements Part 5: Where Does The Code Live?
  149. Design Elements Part 6: Math Operators and Functions
  150. Design Elements Part 7: Statistical Functions
  151. Design Elements Part 8: Summarization Statistical Algorithms
  152. Design Elements Part 9:Representing Data with Statistical Algorithms
  153. Design Elements Part 10: Interpreting the Data—Regression
  154. Design Elements Part 11: String Manipulation
  155. Design Elements Part 12: Loops
  156. Design Elements Part 13: Recursion
  157. Design Elements Part 14: Arrays
  158. Design Elements Part 15: Event-Driven Programming Vs. Scheduled Processes
  159. Design Elements Part 16: Event-Driven Programming
  160. Design Elements Part 17: Program Flow
  161. Forming Queries Part 1: Design
  162. Forming Queries Part 2: Query Basics
  163. Forming Queries Part 3: Query Optimization
  164. Forming Queries Part 4: SET Options
  165. Forming Queries Part 5: Table Optimization Hints
  166. Using SQL Server Templates
  167. Transact-SQL Unit Testing
  168. Index Tuning Wizard
  169. Unicode and SQL Server
  170. SQL Server Development Tools
  171. The SQL Server Transact-SQL Debugger
  172. The Transact-SQL Debugger, Part 2
  173. Basic Troubleshooting for Transact-SQL Code
  174. An Introduction to Spatial Data in SQL Server 2008
  175. Performance Tuning
  176. Performance Tuning SQL Server: Tools and Processes
  177. Performance Tuning SQL Server: Tools Overview
  178. Creating a Performance Tuning Audit - Defining Components
  179. Creating a Performance Tuning Audit - Evaluation Part One
  180. Creating a Performance Tuning Audit - Evaluation Part Two
  181. Creating a Performance Tuning Audit - Interpretation
  182. Creating a Performance Tuning Audit - Developing an Action Plan
  183. Understanding SQL Server Query Plans
  184. Performance Tuning: Implementing Indexes
  185. Performance Monitoring Tools: Windows 2008 (and Higher) Server Utilities, Part 1
  186. Performance Monitoring Tools: Windows 2008 (and Higher) Server Utilities, Part 2
  187. Performance Monitoring Tools: Windows System Monitor
  188. Performance Monitoring Tools: Logging with System Monitor
  189. Performance Monitoring Tools: User Defined Counters
  190. General Transact-SQL (T-SQL) Performance Tuning, Part 1
  191. General Transact-SQL (T-SQL) Performance Tuning, Part 2
  192. General Transact-SQL (T-SQL) Performance Tuning, Part 3
  193. Performance Monitoring Tools: An Introduction to SQL Profiler
  194. Performance Tuning: Introduction to Indexes
  195. Performance Monitoring Tools: SQL Server 2000 Index Tuning Wizard
  196. Performance Monitoring Tools: SQL Server 2005 Database Tuning Advisor
  197. Performance Monitoring Tools: SQL Server Management Studio Reports
  198. Performance Monitoring Tools: SQL Server 2008 Activity Monitor
  199. The SQL Server 2008 Management Data Warehouse and Data Collector
  200. Performance Monitoring Tools: Evaluating Wait States with PowerShell and Excel
  201. Practical Applications
  202. Choosing the Back End
  203. The DBA's Toolbox, Part 1
  204. The DBA's Toolbox, Part 2
  205. Scripting Solutions for SQL Server
  206. Building a SQL Server Lab
  207. Using Graphics Files with SQL Server
  208. Enterprise Resource Planning
  209. Customer Relationship Management (CRM)
  210. Building a Reporting Data Server
  211. Building a Database Documenter, Part 1
  212. Building a Database Documenter, Part 2
  213. Data Management Objects
  214. Data Management Objects: The Server Object
  215. Data Management Objects: Server Object Methods
  216. Data Management Objects: Collections and the Database Object
  217. Data Management Objects: Database Information
  218. Data Management Objects: Database Control
  219. Data Management Objects: Database Maintenance
  220. Data Management Objects: Logging the Process
  221. Data Management Objects: Running SQL Statements
  222. Data Management Objects: Multiple Row Returns
  223. Data Management Objects: Other Database Objects
  224. Data Management Objects: Security
  225. Data Management Objects: Scripting
  226. Powershell and SQL Server - Overview
  227. PowerShell and SQL Server - Objects and Providers
  228. Powershell and SQL Server - A Script Framework
  229. Powershell and SQL Server - Logging the Process
  230. Powershell and SQL Server - Reading a Control File
  231. Powershell and SQL Server - SQL Server Access
  232. Powershell and SQL Server - Web Pages from a SQL Query
  233. Powershell and SQL Server - Scrubbing the Event Logs
  234. SQL Server 2008 PowerShell Provider
  235. SQL Server I/O: Importing and Exporting Data
  236. SQL Server I/O: XML in Database Terms
  237. SQL Server I/O: Creating XML Output
  238. SQL Server I/O: Reading XML Documents
  239. SQL Server I/O: Using XML Control Mechanisms
  240. SQL Server I/O: Creating Hierarchies
  241. SQL Server I/O: Using HTTP with SQL Server XML
  242. SQL Server I/O: Using HTTP with SQL Server XML Templates
  243. SQL Server I/O: Remote Queries
  244. SQL Server I/O: Working with Text Files
  245. Using Microsoft SQL Server on Handheld Devices
  246. Front-Ends 101: Microsoft Access
  247. Comparing Two SQL Server Databases
  248. English Query - Part 1
  249. English Query - Part 2
  250. English Query - Part 3
  251. English Query - Part 4
  252. English Query - Part 5
  253. RSS Feeds from SQL Server
  254. Using SQL Server Agent to Monitor Backups
  255. Reporting Services - Creating a Maintenance Report
  256. SQL Server Chargeback Strategies, Part 1
  257. SQL Server Chargeback Strategies, Part 2
  258. SQL Server Replication Example
  259. Creating a Master Agent and Alert Server
  260. The SQL Server Central Management System: Definition
  261. The SQL Server Central Management System: Base Tables
  262. The SQL Server Central Management System: Execution of Server Information (Part 1)
  263. The SQL Server Central Management System: Execution of Server Information (Part 2)
  264. The SQL Server Central Management System: Collecting Performance Metrics
  265. The SQL Server Central Management System: Centralizing Agent Jobs, Events and Scripts
  266. The SQL Server Central Management System: Reporting the Data and Project Summary
  267. Time Tracking for SQL Server Operations
  268. Migrating Departmental Data Stores to SQL Server
  269. Migrating Departmental Data Stores to SQL Server: Model the System
  270. Migrating Departmental Data Stores to SQL Server: Model the System, Continued
  271. Migrating Departmental Data Stores to SQL Server: Decide on the Destination
  272. Migrating Departmental Data Stores to SQL Server: Design the ETL
  273. Migrating Departmental Data Stores to SQL Server: Design the ETL, Continued
  274. Migrating Departmental Data Stores to SQL Server: Attach the Front End, Test, and Monitor
  275. Tracking SQL Server Timed Events, Part 1
  276. Tracking SQL Server Timed Events, Part 2
  277. Patterns and Practices for the Data Professional
  278. Managing Vendor Databases
  279. Consolidation Options
  280. Connecting to a SQL Azure Database from Microsoft Access
  281. SharePoint 2007 and SQL Server, Part One
  282. SharePoint 2007 and SQL Server, Part Two
  283. SharePoint 2007 and SQL Server, Part Three
  284. Querying Multiple Data Sources from a Single Location (Distributed Queries)
  285. Importing and Exporting Data for SQL Azure
  286. Working on Distributed Teams
  287. Professional Development
  288. Becoming a DBA
  289. Certification
  290. DBA Levels
  291. Becoming a Data Professional
  292. SQL Server Professional Development Plan, Part 1
  293. SQL Server Professional Development Plan, Part 2
  294. SQL Server Professional Development Plan, Part 3
  295. Evaluating Technical Options
  296. System Sizing
  297. Creating a Disaster Recovery Plan
  298. Anatomy of a Disaster (Response Plan)
  299. Database Troubleshooting
  300. Conducting an Effective Code Review
  301. Developing an Exit Strategy
  302. Data Retention Strategy
  303. Keeping Your DBA/Developer Job in Troubled Times
  304. The SQL Server Runbook
  305. Creating and Maintaining a SQL Server Configuration History, Part 1
  306. Creating and Maintaining a SQL Server Configuration History, Part 2
  307. Creating an Application Profile, Part 1
  308. Creating an Application Profile, Part 2
  309. How to Attend a Technical Conference
  310. Tips for Maximizing Your IT Budget This Year
  311. The Importance of Blue-Sky Planning
  312. Application Architecture Assessments
  313. Transact-SQL Code Reviews, Part One
  314. Transact-SQL Code Reviews, Part Two
  315. Cloud Computing (Distributed Computing) Paradigms
  316. NoSQL for the SQL Server Professional, Part One
  317. NoSQL for the SQL Server Professional, Part Two
  318. Object-Role Modeling (ORM) for the Database Professional
  319. Business Intelligence
  320. BI Explained
  321. Developing a Data Dictionary
  322. BI Security
  323. Gathering BI Requirements
  324. Source System Extracts and Transforms
  325. ETL Mechanisms
  326. Business Intelligence Landscapes
  327. Business Intelligence Layouts and the Build or Buy Decision
  328. A Single Version of the Truth
  329. The Operational Data Store (ODS)
  330. Data Marts – Combining and Transforming Data
  331. Designing Data Elements
  332. The Enterprise Data Warehouse — Aggregations and the Star Schema
  333. On-Line Analytical Processing (OLAP)
  334. Data Mining
  335. Key Performance Indicators
  336. BI Presentation - Client Tools
  337. BI Presentation - Portals
  338. Implementing ETL - Introduction to SQL Server 2005 Integration Services
  339. Building a Business Intelligence Solution, Part 1
  340. Building a Business Intelligence Solution, Part 2
  341. Building a Business Intelligence Solution, Part 3
  342. Tips and Troubleshooting
  343. SQL Server and Microsoft Excel Integration
  344. Tips for the SQL Server Tools: SQL Server 2000
  345. Tips for the SQL Server Tools – SQL Server 2005
  346. Transaction Log Troubles
  347. SQL Server Connection Problems
  348. Orphaned Database Users
  349. Additional Resources
  350. Tools and Downloads
  351. Utilities (Free)
  352. Tool Review (Free): DBDesignerFork
  353. Aqua Data Studio
  354. Microsoft SQL Server Best Practices Analyzer
  355. Utilities (Cost)
  356. Quest Software's TOAD for SQL Server
  357. Quest Software's Spotlight on SQL Server
  358. SQL Server on Microsoft's Virtual PC
  359. Red Gate SQL Bundle
  360. Microsoft's Visio for Database Folks
  361. Quest Capacity Manager
  362. SQL Server Help
  363. Visual Studio Team Edition for Database Professionals
  364. Microsoft Assessment and Planning Solution Accelerator
  365. Aggregating Server Data from the MAPS Tool

If you’re looking for more up-to-date information on this topic, please visit our SQL Server article, podcast, and store pages.

It’s ironic that the Relational Database Management System (RDBMS) was invented to implement data structures in something other than files. The irony is that even though the RDBMS doesn't work with independent text files, files are still at the heart of the engine. Of course, the distinction is that SQL Server uses binary files, not simply textual ones, and it’s the internal representation of data that makes an RDBMS special. But it is files all the way down.

A SQL Server database makes use of two types of files. Data is first stored in a transaction log, which is one type of file, and then subsequently written to the second type, the database file. When a user enters a transaction, the data she inserts, updates, or deletes is sent along to the RDBMS engine, which records that line of data in the transaction log. The log is stored in a file with the default extension of LDF (Log Database Format or Log Database File). Once the server has a spare moment, a process spins up to write that line onto the database, which stores the data in a file with the default extension MDF (Microsoft Database Format or Microsoft Database File). But in fact, SQL Server doesn’t even work directly with these filenames for the purpose of accessing data like this. I’ll explain more about that in a moment.

You can assign more than one file to a database, log, or both. When you create a database, the system automatically creates the first two files, one for data and another for logs. But you can (and should) create other files for the database to use.

SQL Server works with files by assigning them to a Filegroup. Even if you have only one file in the database, it will still live in a Filegroup. Let’s take a look at how this works. I’ll create a simple database on a test system, not specifying anything except the name:

CREATE DATABASE FileTest;
GO
Now, I’ll show the Filegroup that automatically showed up for the database:
SELECT * 
FROM sysfilegroups;
GO
----------------------
groupid allocpolicy status groupname
1 0 16 PRIMARY

Sure enough, I have a Filegroup, called “PRIMARY”. SQL Server created that for me. By default, any tables or other objects I have are stored here — which I can change to another Filegroup later. I’ll show you that in a moment.

Within that Filegroup, I have at least one. I’ll use the sysfiles system table to show the actual physical files that are stored in the PRIMARY Filegroup:

SELECT * 
FROM sysfiles a
INNER JOIN sysfilegroups b
ON a.groupid = b.groupid;
GO
-----------------------
fileid groupid size maxsize growth status perf name filename groupid allocpolicy status groupname
1 1 160 -1 128 2 0 FileTest C:\Program Files\Microsoft SQL Server\MSSQL10.SQL2K8\MSSQL\DATA\FileTest.mdf 1 0 16 PRIMARY

Hmmm. I seem to be missing the log file. Let me take a look at the files in the database, without joining them to the Filegroup:

SELECT * 
FROM sysfiles;
GO
--------------
fileid groupid size maxsize growth status perf name filename
1 1 160 -1 128 2 0 FileTest C:\Program Files\Microsoft SQL Server\MSSQL10.SQL2K8\MSSQL\DATA\FileTest.mdf
2 0 63 268435456 10 1048642 0 FileTest_log C:\Program Files\Microsoft SQL Server\MSSQL10.SQL2K8\MSSQL\DATA\FileTest_log.LDF

There it is. You can see that the groupid field for the log file doesn’t have a Filegroup associated with it — which means that while database files are contained within a Filegroup, log files are not. Hold on to that thought a moment.

By the way, I’m using the old style of querying tables for SQL Server 2000. There are new system files and catalogs that you can use in SQL Server 2005 and higher that shows far more information — I’ll switch to those in a moment. For my purposes here, this will work fine.

You can create another file for the database, and place it within any Filegroups you have. Since I have only one Filegroup so far, here’s the way I’ll add another file to it:

ALTER DATABASE FileTest
ADD FILE 
 (NAME = FileTest2,
  FILENAME = 'C:\Program Files\Microsoft SQL Server\MSSQL10.SQL2K8\MSSQL\DATA\FileTest2.mdf'
 )
TO FILEGROUP PRIMARY;
GO

Using the earlier queries, I can show the new file that I just added.

As I begin to create objects in this new database, SQL Server handles the files in an interesting way. For any kind of data-bearing object (mostly tables and indexes), SQL Server fills up one transaction log before it uses the next one, if there are indeed more than one. The log process then writes to ALL of the data files in the Filegroup, sort of like filling up multiple glasses of water from the bottom up all at once. That keeps everything very balanced.

So why is this all important?

Ah — therein lies the beauty of this approach. Let’s assume you have a few hard drives in your system, and you want to balance the reads and writes from the database across all of them. By adding a file from another drive to the Filegroup, SQL Server will automatically allow the drives to spin their fastest, making your system faster. Also, if you have less space than you need for an entire database on one drive, you can use multiple drives.

So large tables and indexes can now take advantage of multiple drives. But wait, I mentioned that SQL Server automatically balances out the reads and writes across all of the files in a Filegroup. What if you want more control? What if you would like to put the tables on one file (which is on a certain drive) and the indexes on another file (which is on another drive) so that the updates to the table and the index can happen at the same time?

You can create another Filegroup. Like this:

ALTER DATABASE FileTest
ADD FILEGROUP Secondary;
GO

Now you can add files to that Filegroup, just like I did earlier, by changing the ON FILEGROUP part of the ALTER DATABASE statement.

Using Filegroups

Simply adding a Filegroup to a database, and then adding files to that, doesn’t place any data there. Just having the Filegroup doesn't allow the data to "spill over" into that space automatically. You have to specify where you’d like tables or indexes to go. You can do that when you create a table or index graphically (under the Properties menu item in SQL Server Management Studio or Enterprise Manager), or by using SQL Data Manipulation Commands (DML) like this:

CREATE TABLE [dbo].[tbl_Test] (
 [Test_ID] [int] IDENTITY (1, 1) NOT NULL ,
 [Test_Name] [char] (10) 
) ON [SECONDARY]
GO

The ON [SECONDARY] part of this statement is where you set a table to use a particular Filegroup.

Using Filegroups (and by extension, files), you can selectively place data on your storage subsystem. Performance is enhanced when you place a heavily-read table on a different physical device than another table which is written to at the same time. Using this logic, placing indexes and the tables they support on separate files is often a great way to increase performance.

Of course, if you’ve made two drive letters on the same physical device, say in a SAN environment or on a RAID system, creating separate files and filegroups doesn’t really help performance at all. When I mention drive letters, I'm not just talking about a single physical drive with multiple letters. Those are still on the same set of spindles on the drive. I'm talking about a separate physical drive, channel and I/O processor. Within a SAN, this becomes more problematic to figure out, since the Logical Unit Number (LUN) presented to you may be carved out of several physical drives anyway. In these cases, work with your storage engineer to come up with a viable strategy for drive layouts.

A good strategy to determine your Filegroup layouts is to check whether a table has heavy read or write operations. Then look for other heavy read or write tables and try to separate those from each other.

As I mentioned earlier, it’s also helpful to place indexes on devices opposite the tables they support, so that indexing activities don’t interfere with heavy inserts, such as during Extract, Transform, and Load (ETL) operations.

It’s also best to separate the transaction log files from the database files, so that data being written to the log doesn’t slow down write or read operations from the database. Again, this only helps if the devices on which you place your Filegroups are physically separated from each other. Also, for the best performance gain, it’s best to make sure the drives have their own controllers or channels. On IDE controllers (if you’re forced to use them in a database environment), the second channel is often slower than the primary one.

The tempdb database, which SQL Server uses for sorts and other operations, should also have its own drive or channel. Since some queries will sort the data at the same time that other queries are reading or writing to the database, it’s best to keep them apart.

In fact, any activity which would be useful to have operating at the same time as another activity, such as reading from a table and writing to another, or writing to a table and updating its index at the same time, or writing data to the log file and then having it write out to the database, are candidates for keeping the physical devices where they live separate.

Of course, that’s not really possible. Having a different physical device for every activity would cause you to have dozens, or hundreds of drives. That can be a bit much. But there are some things you should keep separate from each other where possible:

  • Tables
  • Indexes
  • TempDB
  • Logs
  • Backup files
  • Operating system files
  • Operating system cache
  • Full Text catalogs and indexes
  • Replication shares

I know, that looks like a lot of physical drives. And it’s not going to be the end of the world to put everything on a well-performing SAN system. But if you can separate these functions onto different physical devices, you should.

Another use of files and Filegroups has to do with disaster recovery. If you keep a running backup of your database and separate the transaction log to another device, then — should the database drive fail — you have the means to restore the database from tape, and apply the logs from the separate device. Since the log contains the transactions since the last backup (assuming you’re running in the Full recovery model), all the data is safe.

You can also backup and restore both files and Filegroups. In fact, the only way to back up a single table in SQL Server is to place it on its own file. You might do this because there isn’t enough time to back up the whole database, or perhaps you’ve got a tape capacity issue.

To perform a file or Filegroup backups, your database has to be in either the Full or Bulk-Logged recovery model. The reason for this is that you have to apply the transaction log as part of the restore so that the database "knows" where it is. Here’s the syntax for a file backup:

USE master
GO
BACKUP DATABASE FilesArticle
 FILE = ’FilesArticle_Two_Data’,
 FILEGROUP = ’SECONDARY’,
 TO FilesArticle_Backup_DeviceName
GO 

This syntax makes use of a Backup Device called FilesArticle_Backup_DeviceName. You could also use a file name or tape name here.

To restore this backup, as I mentioned, you’ll have to apply the transaction log. Here’s that syntax:

USE master
GO
-- Restore the files and Filesgroups for FilesArticle
RESTORE DATABASE FilesArticle
 FILE = ’FilesArticle_Two_Data’,
 FILEGROUP = ’SECONDARY’
 FROM FilesArticle_Backup_DeviceName
 WITH NORECOVERY
GO
-- Apply the first transaction log backup
RESTORE LOG FilesArticle
 FROM FilesArticle_log1
 WITH NORECOVERY
GO
-- Run through the same process for all logs, then
-- Apply the last transaction log backup
RESTORE LOG FilesArticle
 FROM FilesArticle_log2
 WITH RECOVERY
GO

Notice that I restore the database and then apply all logs forward, using the WITH RECOVERY only at the end.

You can also perform file and Filegroup backups using Enterprise Manager or SQL Server Management Studio if you’re more graphically inclined.

This has been a short introduction to implementing files and Filegroups in your databases. Make sure you check out the references at the end of the article to learn more about optimizing your system this way.

InformIT Articles and Sample Chapters

I have another article on SQL Server I/O, appropriately titled Storage — SQL Server I/O.

Books and eBooks

Ken Henderson has an excellent book on troubleshooting that also covers files, SQL Server 2005 Practical Troubleshooting: The Database Engine (also available as a downloadable eBook and in Safari Books Online).

Online Resources

Paul Randal is quite possibly “the” reference for SQL Server files. He worked on the Microsoft team that created that part of the product. Check out his blog here.

InformIT Promotional Mailings & Special Offers

I would like to receive exclusive offers and hear about products from InformIT and its family of brands. I can unsubscribe at any time.

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For orders and purchases placed through our online store on this site, we collect order details, name, institution name and address (if applicable), email address, phone number, shipping and billing addresses, credit/debit card information, shipping options and any instructions. We use this information to complete transactions, fulfill orders, communicate with individuals placing orders or visiting the online store, and for related purposes.

Surveys

Pearson may offer opportunities to provide feedback or participate in surveys, including surveys evaluating Pearson products, services or sites. Participation is voluntary. Pearson collects information requested in the survey questions and uses the information to evaluate, support, maintain and improve products, services or sites, develop new products and services, conduct educational research and for other purposes specified in the survey.

Contests and Drawings

Occasionally, we may sponsor a contest or drawing. Participation is optional. Pearson collects name, contact information and other information specified on the entry form for the contest or drawing to conduct the contest or drawing. Pearson may collect additional personal information from the winners of a contest or drawing in order to award the prize and for tax reporting purposes, as required by law.

Newsletters

If you have elected to receive email newsletters or promotional mailings and special offers but want to unsubscribe, simply email information@informit.com.

Service Announcements

On rare occasions it is necessary to send out a strictly service related announcement. For instance, if our service is temporarily suspended for maintenance we might send users an email. Generally, users may not opt-out of these communications, though they can deactivate their account information. However, these communications are not promotional in nature.

Customer Service

We communicate with users on a regular basis to provide requested services and in regard to issues relating to their account we reply via email or phone in accordance with the users' wishes when a user submits their information through our Contact Us form.

Other Collection and Use of Information


Application and System Logs

Pearson automatically collects log data to help ensure the delivery, availability and security of this site. Log data may include technical information about how a user or visitor connected to this site, such as browser type, type of computer/device, operating system, internet service provider and IP address. We use this information for support purposes and to monitor the health of the site, identify problems, improve service, detect unauthorized access and fraudulent activity, prevent and respond to security incidents and appropriately scale computing resources.

Web Analytics

Pearson may use third party web trend analytical services, including Google Analytics, to collect visitor information, such as IP addresses, browser types, referring pages, pages visited and time spent on a particular site. While these analytical services collect and report information on an anonymous basis, they may use cookies to gather web trend information. The information gathered may enable Pearson (but not the third party web trend services) to link information with application and system log data. Pearson uses this information for system administration and to identify problems, improve service, detect unauthorized access and fraudulent activity, prevent and respond to security incidents, appropriately scale computing resources and otherwise support and deliver this site and its services.

Cookies and Related Technologies

This site uses cookies and similar technologies to personalize content, measure traffic patterns, control security, track use and access of information on this site, and provide interest-based messages and advertising. Users can manage and block the use of cookies through their browser. Disabling or blocking certain cookies may limit the functionality of this site.

Do Not Track

This site currently does not respond to Do Not Track signals.

Security


Pearson uses appropriate physical, administrative and technical security measures to protect personal information from unauthorized access, use and disclosure.

Children


This site is not directed to children under the age of 13.

Marketing


Pearson may send or direct marketing communications to users, provided that

  • Pearson will not use personal information collected or processed as a K-12 school service provider for the purpose of directed or targeted advertising.
  • Such marketing is consistent with applicable law and Pearson's legal obligations.
  • Pearson will not knowingly direct or send marketing communications to an individual who has expressed a preference not to receive marketing.
  • Where required by applicable law, express or implied consent to marketing exists and has not been withdrawn.

Pearson may provide personal information to a third party service provider on a restricted basis to provide marketing solely on behalf of Pearson or an affiliate or customer for whom Pearson is a service provider. Marketing preferences may be changed at any time.

Correcting/Updating Personal Information


If a user's personally identifiable information changes (such as your postal address or email address), we provide a way to correct or update that user's personal data provided to us. This can be done on the Account page. If a user no longer desires our service and desires to delete his or her account, please contact us at customer-service@informit.com and we will process the deletion of a user's account.

Choice/Opt-out


Users can always make an informed choice as to whether they should proceed with certain services offered by InformIT. If you choose to remove yourself from our mailing list(s) simply visit the following page and uncheck any communication you no longer want to receive: www.informit.com/u.aspx.

Sale of Personal Information


Pearson does not rent or sell personal information in exchange for any payment of money.

While Pearson does not sell personal information, as defined in Nevada law, Nevada residents may email a request for no sale of their personal information to NevadaDesignatedRequest@pearson.com.

Supplemental Privacy Statement for California Residents


California residents should read our Supplemental privacy statement for California residents in conjunction with this Privacy Notice. The Supplemental privacy statement for California residents explains Pearson's commitment to comply with California law and applies to personal information of California residents collected in connection with this site and the Services.

Sharing and Disclosure


Pearson may disclose personal information, as follows:

  • As required by law.
  • With the consent of the individual (or their parent, if the individual is a minor)
  • In response to a subpoena, court order or legal process, to the extent permitted or required by law
  • To protect the security and safety of individuals, data, assets and systems, consistent with applicable law
  • In connection the sale, joint venture or other transfer of some or all of its company or assets, subject to the provisions of this Privacy Notice
  • To investigate or address actual or suspected fraud or other illegal activities
  • To exercise its legal rights, including enforcement of the Terms of Use for this site or another contract
  • To affiliated Pearson companies and other companies and organizations who perform work for Pearson and are obligated to protect the privacy of personal information consistent with this Privacy Notice
  • To a school, organization, company or government agency, where Pearson collects or processes the personal information in a school setting or on behalf of such organization, company or government agency.

Links


This web site contains links to other sites. Please be aware that we are not responsible for the privacy practices of such other sites. We encourage our users to be aware when they leave our site and to read the privacy statements of each and every web site that collects Personal Information. This privacy statement applies solely to information collected by this web site.

Requests and Contact


Please contact us about this Privacy Notice or if you have any requests or questions relating to the privacy of your personal information.

Changes to this Privacy Notice


We may revise this Privacy Notice through an updated posting. We will identify the effective date of the revision in the posting. Often, updates are made to provide greater clarity or to comply with changes in regulatory requirements. If the updates involve material changes to the collection, protection, use or disclosure of Personal Information, Pearson will provide notice of the change through a conspicuous notice on this site or other appropriate way. Continued use of the site after the effective date of a posted revision evidences acceptance. Please contact us if you have questions or concerns about the Privacy Notice or any objection to any revisions.

Last Update: November 17, 2020