go backsqlschool blogs list

Maximum Capacity Specifications for SQL Server 2005 Database Engine

by Antonios Chatzipavlis

Επειδή αρκετές φορές με ρωτούν αν ο SQL Server έχει κάποια όρια σας παραθέτω τα όρια του

Database Engine Object

x32 x64

Batch size1

65,536 * Network Packet Size

65,536 * Network Packet Size

Bytes per short string column

8,000

8,000

Bytes per GROUP BY, ORDER BY

8,060

8,060

Bytes per index key2

900

900

Bytes per foreign key

900

900

Bytes per primary key

900

900

Bytes per row8

8,060

8,060

Bytes in source text of a stored procedure

Lesser of batch size or 250 MB

Lesser of batch size or 250 MB

Bytes per varchar(max), varbinary(max), xml, text, or image column

2^31-1

2^31-1

Characters per ntext or nvarchar(max) column

2^30-1

2^30-1

Clustered indexes per table

1

1

Columns in GROUP BY, ORDER BY

Limited only by number of bytes

Limited only by number of bytes

Columns or expressions in a GROUP BY WITH CUBE or WITH ROLLUP statement

10

10

Columns per index key7

16

16

Columns per foreign key

16

16

Columns per primary key

16

16

Columns per base table

1,024

1,024

Columns per SELECT statement

4,096

4,096

Columns per INSERT statement

1,024

1,024

Connections per client

Maximum value of configured connections

Maximum value of configured connections

Database size

1,048,516 terabytes

1,048,516 terabytes

Databases per instance of SQL Server

32,767

32,767

Filegroups per database

32,767

32,767

Files per database

32,767

32,767

File size (data)

16 terabytes

16 terabytes

File size (log)

2 terabytes

2 terabytes

Foreign key table references per table4

253

253

Identifier length (in characters)

128

128

Instances per computer

16

16

Length of a string containing SQL statements (batch size)1

65,536 * Network packet size

65,536 * Network packet size

Locks per connection

Maximum locks per server

Maximum locks per server

Locks per instance of SQL Server5

Up to 2,147,483,647

Limited only by memory

Nested stored procedure levels6

32

32

Nested subqueries

32

32

Nested trigger levels

32

32

Nonclustered indexes per table

249

249

Parameters per stored procedure

2,100

2,100

Parameters per user-defined function

2,100

2,100

REFERENCES per table

253

253

Rows per table

Limited by available storage

Limited by available storage

Tables per database3

Limited by number of objects in a database

Limited by number of objects in a database

Partitions per partitioned table or index

1,000

1,000

Statistics on non-indexed columns

2,000

2,000

Tables per SELECT statement

256

256

Triggers per table3

Limited by number of objects in a database

Limited by number of objects in a database

UNIQUE indexes or constraints per table

249 nonclustered and 1 clustered

249 nonclustered and 1 clustered

User connections

32,767

32,767

XML indexes

249

249

1 Network Packet Size is the size of the tabular data stream (TDS) packets used to communicate between applications and the relational Database Engine. The default packet size is 4 kilobytes (KB), and is controlled by the network packet size configuration option.

2 The maximum number of bytes in any index key cannot exceed 900 in SQL Server 2005. You can define a key using variable-length columns whose maximum sizes add up to more than 900, provided no row is ever inserted with more than 900 bytes of data in those columns. In SQL Server 2005, you can include nonkey columns in a nonclustered index to avoid the maximum index key size of 900 bytes. For more information, see Index with Included Columns.

3 Database objects include objects such as tables, views, stored procedures, user-defined functions, triggers, rules, defaults, and constraints. The sum of the number of all objects in a database cannot exceed 2,147,483,647.

4 Although a table can contain an unlimited number of FOREIGN KEY constraints, the recommended maximum is 253. Depending on the hardware configuration hosting SQL Server, specifying additional foreign key constraints may be expensive for the query optimizer to process.

5 This value is for static lock allocation. Dynamic locks are limited only by memory.

6 If a stored procedure accesses more than 8 databases, or more than 2 databases in interleaving, you will receive an error.

7 If the table contains one or more XML indexes, the clustering key of the user table is limited to 15 columns because the XML column is added to the clustering key of the primary XML index. In SQL Server 2005, you can include nonkey columns in a nonclustered index to avoid the limitation of a maximum of 16 key columns. For more information, see Index with Included Columns.

8 SQL Server 2005 supports row-overflow storage which enables variable length columns to be pushed off-row. Only a 24-byte root is stored in the main record for variable length columns pushed out of row; because of this, the effective row limit is higher than in previous releases of SQL Server. For more information, see the "Row-Overflow Data Exceeding 8 KB" topic in SQL Server 2005 Books Online.

Ημερομηνία: 01 August 2009 14:04
Αξιολόγηση:
Κατηγορίες:
Tags:
Share it:

Αφήστε το σχόλιο σας - Leave your comment

Τα σχόλια έχουν κλείσει.
Επιτρέπονται μόνο τα σχόλια από τα μέλη του SqlSchool.gr.


newsletter subscription

Εάν επιθυμείτε να λαμβάνετε ενημέρωση από εμάς, δώστε μας το e-mail σας.
PASS chapter logo
Official Professional Association for SQL Server (PASS) chapter for Greece
Join to PASS