Maximum Capacity Specifications for SQL Server 2005
Updated: 15 September 2007
The following tables specify the maximum sizes and numbers of various objects defined in Microsoft SQL Server 2005 components.
Database Engine Objects
The following table specifies the maximum sizes and numbers of various objects defined in SQL Server 2005 databases or referenced in Transact-SQL statements. The table does not include SQL Server Windows CE Edition.
SQL Server 2005 Database Engine object
Maximum sizes/numbers SQL Server 2005 (32-bit)
Maximum sizes/numbers SQL Server 2005 (64-bit)
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 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
524,258 terabytes
524,258 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
50 instances on a stand-alone server for all SQL Server 2005 editions except for Workgroup Edition. Workgroup Edition supports a maximum of 16 instances.
SQL Server 2005 supports 25 instances on a failover cluster.
50 instances on a stand-alone server.
25 instances on a failover cluster.
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
1Network 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.
2The 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.
3Database 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.
4Although 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.
5This value is for static lock allocation. Dynamic locks are limited only by memory.
6If a stored procedure accesses more than 8 databases, or more than 2 databases in interleaving, you will receive an error.
7If 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.
8SQL 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.
Replication Objects
The following table specifies the maximum sizes and numbers of various objects defined in SQL Server 2005 Replication. The table does not include SQL Server Windows CE Edition.
SQL Server 2005 Replication object
Maximum sizes/numbers SQL Server 2005 (32-bit)
Maximum sizes/numbers SQL Server 2005 (64-bit)
Articles (merge publication)
256
256
Articles (snapshot or transactional publication)
32,767
32,767
Columns in a table1 (merge publication)
246
246
Columns in a table2 (SQL Server snapshot or transactional publication)
1000
1000
Columns in a table2 (Oracle snapshot or transactional publication)
995
995
Bytes for a column used in a row filter (merge publication)
1024
1024
Bytes for a column used in a row filter (snapshot or transactional publication)
8000
8000
1If row tracking is used for conflict detection (the default), the base table can include a maximum of 1,024 columns, but columns must be filtered from the article so that a maximum of 246 columns is published. If column tracking is used, the base table can include a maximum of 246 columns. For more information on the tracking level, see the "Tracking Level" section of How Merge Replication Detects and Resolves Conflicts.
2The base table can include the maximum number of columns allowable in the publication database (1,024 for SQL Server), but columns must be filtered from the article if they exceed the maximum specified for the publication type.
See Also
Reference
Hardware and Software Requirements for Installing SQL Server 2005
Check Parameters for the System Configuration Checker
Other Resources
Installing SQL Server 2005 Components
Help and Information
Getting SQL Server 2005 Assistance
Updated: 15 September 2007
The following tables specify the maximum sizes and numbers of various objects defined in Microsoft SQL Server 2005 components.
Database Engine Objects
The following table specifies the maximum sizes and numbers of various objects defined in SQL Server 2005 databases or referenced in Transact-SQL statements. The table does not include SQL Server Windows CE Edition.
SQL Server 2005 Database Engine object
Maximum sizes/numbers SQL Server 2005 (32-bit)
Maximum sizes/numbers SQL Server 2005 (64-bit)
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 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
524,258 terabytes
524,258 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
50 instances on a stand-alone server for all SQL Server 2005 editions except for Workgroup Edition. Workgroup Edition supports a maximum of 16 instances.
SQL Server 2005 supports 25 instances on a failover cluster.
50 instances on a stand-alone server.
25 instances on a failover cluster.
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
1Network 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.
2The 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.
3Database 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.
4Although 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.
5This value is for static lock allocation. Dynamic locks are limited only by memory.
6If a stored procedure accesses more than 8 databases, or more than 2 databases in interleaving, you will receive an error.
7If 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.
8SQL 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.
Replication Objects
The following table specifies the maximum sizes and numbers of various objects defined in SQL Server 2005 Replication. The table does not include SQL Server Windows CE Edition.
SQL Server 2005 Replication object
Maximum sizes/numbers SQL Server 2005 (32-bit)
Maximum sizes/numbers SQL Server 2005 (64-bit)
Articles (merge publication)
256
256
Articles (snapshot or transactional publication)
32,767
32,767
Columns in a table1 (merge publication)
246
246
Columns in a table2 (SQL Server snapshot or transactional publication)
1000
1000
Columns in a table2 (Oracle snapshot or transactional publication)
995
995
Bytes for a column used in a row filter (merge publication)
1024
1024
Bytes for a column used in a row filter (snapshot or transactional publication)
8000
8000
1If row tracking is used for conflict detection (the default), the base table can include a maximum of 1,024 columns, but columns must be filtered from the article so that a maximum of 246 columns is published. If column tracking is used, the base table can include a maximum of 246 columns. For more information on the tracking level, see the "Tracking Level" section of How Merge Replication Detects and Resolves Conflicts.
2The base table can include the maximum number of columns allowable in the publication database (1,024 for SQL Server), but columns must be filtered from the article if they exceed the maximum specified for the publication type.
See Also
Reference
Hardware and Software Requirements for Installing SQL Server 2005
Check Parameters for the System Configuration Checker
Other Resources
Installing SQL Server 2005 Components
Help and Information
Getting SQL Server 2005 Assistance
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