Hướng dẫn học Microsoft SQL Server 2008 part 93 docx

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Configuring SQL Server
IN THIS CHAPTER
Making sense of SQL Server
configuration
Configuring the server-level
configuration options
Configuring the database-level
configuration options
Configuring the
connection-level options
S
QL Server has a plethora of configuration options. The difficulty in master-
ing them lies in the fact that they are spread across three levels:
■ Server-level options generally configure how the server works with
hardware, and determine the database defaults.
■ Database-level options determine the behavior of the database, and set
the connection-level defaults.
■ Connection-level options determine the current behaviors within the
connection or current procedure.
Several of the configuration options overlap or simply set the default for the
level immediately below. This chapter pulls these three configuration levels into
a single unified understanding of how they relate to and affect each other. This
chapter does not cover every single SQL Server configuration option but it covers
most of them that I think are important. If you are a SQL Server beginner, you
may find that some of the configuration options are advanced and you may not
need them immediately.
Setting the Options
Whether you choose to adjust the properties from SQL Server Management

Studio’s graphical tool or from code is completely up to you, but not every
property is available from Management Studio using the graphical interface.
While the graphical interface has the advantage of being easy to use, and walks
you through easily understood dialogs that prompt for the possible options in
a pick-and-choose format, it lacks the repeatability of a T-SQL script run as a
query.
To view miscellaneous information about the com-
puter system while configuring SQL Server, query the
sys.dm_os_sys_info dynamic management view.
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New in SQL Server 2008 Configuration
S
QL Server 2008 offers many new configuration options, such as backup compression default
and filestream access level, that give the SQL DBA much more control in configuring SQL
Server 2008.
The configuration options set working set size, open objects,andlocks are still present in the
sp_configure stored procedure, but their functionality is unavailable in SQL Server 2008. These options
have no effect.
Configuring the server
The server-level configuration options control server-wide settings, such as how SQL Server interacts
with hardware, how it multi-threads within Windows, and whether triggers are permitted to fire other
triggers. When configuring the server, keep in mind the goals of configuration: consistency and perfor-
mance.
Graphically, many o f the server options may be configured within the Server Properties page, which you
can open by right-clicking a server in the console tree and choosing Properties from the context menu.
The General tab in Management Studio’s SQL Server Properties dialog (see Figure 39-1) reports the ver-
sions and environment of the server.

The same information is available to code. For example, the version may be identified with the
@@VERSION global variable:
select @@VERSION;
Result:
Microsoft SQL Server 2008 (RTM) - 10.0.1600.22 (Intel X86)
Jul 9 2008 14:43:34
Copyright (c) 1988-2008 Microsoft Corporation
Enterprise Edition on Windows NT 5.2 <X86> (Build 3790: Service
Pack 2)
The first line of the preceding result includes the product version of SQL Server. In this example, the
SQL Server product version is 10.0.1600.22. The last line of the result can be confusing. It reports the
edition of SQL Server. In this example, it is SQL Server 2008 Enterprise Edition, but the service pack
reported in the last line is the Windows service pack level and not the SQL Server service pack level.
In this example, it is SP2 for Windows Server 2003. That is one of the reasons why I don’t like to use
the
SELECT @@VERSION command. Instead, I prefer to use the SERVERPROPERTY system function to
determine the information. The advantage of this method is that the function may be used as an expres-
sion within a
SELECT statement. The following example uses the SERVERPROPERTY function to return
the SQL Server product version, product level, and edition:
SELECT
SERVERPROPERTY(’ProductVersion’) AS ProductVersion,
SERVERPROPERTY(’ProductLevel’) AS ProductLevel,
SERVERPROPERTY(’Edition’) AS Edition;
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Configuring SQL Server 39
FIGURE 39-1
The General tab of Management Studio’s Server Properties dialog

Result:
ProductVersion ProductLevel Edition
10.0.1600.22 RTM Enterprise Edition
In the preceding result, the ProductVersion indicates the SQL Server product version number. The
ProductLevel indicates the SQL Server product level. At the time of writing this chapter, we did not
have any service packs f or SQL Server 2008 and the product level is
RTM (Release to Manufacturing).
If a SQL Server service pack is installed, the product level will indicate the service pack level too.
For example, if you run the preceding command against your SQL Server 2005 SP3 instance, the
ProductLevel will return SP3. The Edition indicates the SQL Server edition.
Many of the configuration properties do not take effect until SQL Server is restarted, so the
General tab in the SQL Server Properties (Configure) dialog box displays the current run-
ning values.
Within code, many of the server properties are set by means of the sp_configure system stored pro-
cedure. When executed without any parameters, this procedure reports the current settings, as in the
following code (word-wrap adjusted to fit on the page):
EXEC sp_configure;
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Result:
name minimum maximum config_value
run_value

allow updates 0 1 0 0
backup compression default 0 1 0 0
clr enabled 0 1 0 0
cross db ownership chaining 0 1 0 0
default language 0 9999 0 0

filestream access level 0 2 2 2
max text repl size (B) −1 2147483647 65536 65536
nested triggers 0 1 1 1
remote access 0 1 1 1
remote admin connections 0 1 0 0
remote login timeout (s) 0 2147483647 20 20
remote proc trans 0 1 0 0
remote query timeout (s) 0 2147483647 600 600
server trigger recursion 0 1 1 1
show advanced options 0 1 0 0
user options 0 32767 0 0
You can always discover the minimum and maximum values for a particular configuration
option by running the
sp_configure command with the option, but without any value. For
example, run
EXEC sp_configure ‘remote login timeout’;
and you’ll discover that the remote login timeout configuration option can have any value in the
range of 0 to 2,147,483,647.
The extended stored procedure xp_msver reports additional server and environment properties:
EXEC xp_msver;
Result:
Index Name Internal_Value Character_Value
1 ProductName NULL Microsoft SQL Server
2 ProductVersion 655360 10.0.1600.22
3 Language 1033 English (United States)
4 Platform NULL NT INTEL X86
5 Comments NULL SQL
6 CompanyName NULL Microsoft Corporation
7 FileDescription NULL SQL Server Windows NT
8 FileVersion NULL 2007.0100.1600.022

((SQL_PreRelease).080709-1414 )
9 InternalName NULL SQLSERVR
10 LegalCopyright NULL Microsoft Corp. All
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Configuring SQL Server 39
rights reserved.
11 LegalTrademarks NULL Microsoft SQL Server is
a registered trademark of Microsoft Corporation.
12 OriginalFilename NULL SQLSERVR.EXE
13 PrivateBuild NULL NULL
14 SpecialBuild 116588544 NULL
15 WindowsVersion 393281542 5.2 (3790)
16 ProcessorCount 1 1
17 ProcessorActiveMask 1 00000001
18 ProcessorType 586 PROCESSOR_INTEL_PENTIUM
19 PhysicalMemory 2046 2046 (2145845248)
20 Product ID NULL NULL
The information returned by sp_configure is settable, but the information returned by
xp_msver is not.
Configuring the database
The database-level options configure the current database’s behavior regarding ANSI compatibility and
recovery.
Most database options can be set in Management Studio within the Database Properties page, which
you can access by right-clicking a database in the console tree and choosing Properties from the context
menu. The Options tab is shown in Figure 39-2.
The database configuration options can be set using T-SQL
ALTER DATABASE SET options. The follow-
ing example sets the

AdventureWorks2008 database to single-user mode to obtain exclusive access:
ALTER DATABASE AdventureWorks2008 SET SINGLE_USER;
View database configuration options using the sys.databases catalog view or the
DATABASEPROPERTYEX() function. The following example returns all the database properties of
the
AdventureWorks2008 database:
SELECT * FROM sys.databases WHERE name = ‘AdventureWorks2008’;
Do not use the sp_dboption system stored procedure, as it will be removed in the next
version of SQL Server.
Configuring the connection
Many of the c onnection-level options configure ANSI compatibility or specific connection-performance
options.
Connection-level options are very limited in scope. If the option is set within an interactive session, then
the setting is in force until it’s changed or the session ends. If the option is set within a stored proce-
dure, then the setting persists only for the life of that stored procedure.
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FIGURE 39-2
Management Studio’s Database Properties Options tab can be used to configure the most common
database properties
The connection-level options are typically configured by means of the SET command. The following
code configures how SQL Server handles
nulls within this current session:
SET ANSI_NULLS OFF;
Result:
Command(s) completed successfully.
Connection properties can also be checked by means of the SessionProperty() function:
Select SESSIONPROPERTY (’ANSI_NULLS’);

Result:
0
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Management Studio allows you to set several query properties. You can review and set these properties
for current queries by clicking the Query menu and then Query Options. For all future connections,
review and set the properties by clicking the Tools menu a nd then Options. Figure 39-3 shows an
example of the ANSI settings that SQL Server will use to run the queries.
To view current settings of connection-level options, query the sys.dm_exec_connections
dynamic management view.
FIGURE 39-3
The ANSI settings that SQL Server uses to run your queries
Configuration Options
Because so many similar configuration options are c ontrolled by different commands and at different lev-
els (server, database, connection), this section organizes the configuration options by topic, rather than
command or level.
Displaying the advanced options
As with many operations, displaying advanced options can be achieved using several methods. One
method is to query the
sys.configurations catalog view as shown here:
SELECT name, minimum, maximum, value, value_in_use
FROM sys.configurations
WHERE is_advanced = 1
ORDER BY name;
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The preceding example will display all the SQL Server advanced options. To display all the o ptions,
comment the
WHERE clause. Another method to display the advanced options is to turn on the show
advanced options
configuration, as follows:
EXEC sp_configure ‘show advanced options’, 1;
RECONFIGURE;
After a configuration setting is changed with sp_configure,theRECONFIGURE command
causes the changes to take effect. If you don’t run
RECONFIGURE, then the config_value
field will still show the change, but the change won’t appear in the run_value field, even if you restart
the service. Some configuration changes take effect only after SQL Server is restarted.
After you enable the advanced option display, you can use the sp_configure command to display a
list of all of the options:
EXEC sp_configure;
Result (with advanced options enabled):
name minimum maximum config_value
run_value


access check cache bucket count 0 16384 0 0
access check cache quota 0 2147483647 0 0
Ad Hoc Distributed Queries 0 1 0 0
affinity I/O mask -2147483648 2147483647 0 0
affinity64 I/O mask -2147483648 2147483647 0 0
affinity mask -2147483648 2147483647 0 0
affinity64 mask -2147483648 2147483647 0 0
Agent XPs 0 1 1 1
allow updates 0 1 0 0
awe enabled 0 1 0 0

backup compression default 0 1 0 0
blocked process threshold (s) 0 86400 0 0
c2 audit mode 0 1 0 0
clr enabled 0 1 0 0
common criteria compliance enabled 0 1 0 0
cost threshold for parallelism 0 32767 5 5
cross db ownership chaining 0 1 0 0
cursor threshold -1 2147483647 -1 -1
Database Mail XPs 0 1 0 0
default full-text language 0 2147483647 1033
1033
default language 0 9999 0 0
default trace enabled 0 1 1 1
disallow results from triggers 0 1 0 0
EKM provider enabled 0 1 0 0
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filestream access level 0 2 2 2
fill factor (%) 0 100 0 0
ft crawl bandwidth (max) 0 32767 100 100
ft crawl bandwidth (min) 0 32767 0 0
ft notify bandwidth (max) 0 32767 100 100
ft notify bandwidth (min) 0 32767 0 0
index create memory (KB) 704 2147483647 0 0
in-doubt xact resolution 0 2 0 0
lightweight pooling 0 1 0 0
locks 5000 2147483647 0 0
max degree of parallelism 0 64 0 0

max full-text crawl range 0 256 4 4
max server memory (MB) 16 2147483647 2147483647
2147483647
max text repl size (B) -1 2147483647 65536
65536
max worker threads 128 32767 0 0
media retention 0 365 0 0
min memory per query (KB) 512 2147483647 1024
1024
min server memory (MB) 0 2147483647 0 0
nested triggers 0 1 1 1
network packet size (B) 512 32767 4096
4096
Ole Automation Procedures010 0
open objects 0 2147483647 0 0
optimize for ad hoc workloads 0 1 0 0
PH timeout (s) 1 3600 60 60
precompute rank 0 1 0 0
priority boost 0 1 0 0
query governor cost limit 0 2147483647 0 0
query wait (s) -1 2147483647 -1 -1
recovery interval (min) 0 32767 0 0
remote access 0 1 1 1
remote admin connections 0 1 0 0
remote login timeout (s) 0 2147483647 20 20
remote proc trans 0 1 0 0
remote query timeout (s) 0 2147483647 600
600
Replication XPs 0 1 0 0
scan for startup procs 0 1 0 0

server trigger recursion 0 1 1 1
set working set size 0 1 0 0
show advanced options 0 1 1 1
SMO and DMO XPs 0 1 1 1
SQL Mail XPs 0 1 0 0
transform noise words 0 1 0 0
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