|
Object
|
Maximum sizes/numbers
SQL Server (32-bit)
|
Maximum sizes/numbers
SQL Server (64-bit)
|
|
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 nonwide
table
|
1,024
|
1,024
|
|
Columns per wide table
|
30,000
|
30,000
|
|
Columns per SELECT
statement
|
4,096
|
4,096
|
|
Columns per INSERT
statement
|
4096
|
4096
|
|
Connections per client
|
Maximum value of
configured connections
|
Maximum value of
configured connections
|
|
Database size
|
524,272 terabytes
|
524,272 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 editions.
|
50 instances on a
stand-alone server.
|
|
SQL Server supports 25
instances on a failover cluster.
|
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
|
999
|
999
|
|
Number of distinct
expressions in the GROUP BY clause when any of the following are present:
CUBE, ROLLUP, GROUPING SETS, WITH CUBE, WITH ROLLUP
|
32
|
32
|
|
Number of grouping
sets generated by operators in the GROUP BY clause
|
4,096
|
4,096
|
|
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
|
30,000
|
30,000
|
|
Tables per SELECT
statement
|
Limited only by
available resources
|
Limited only by
available resources
|
|
Triggers per table3
|
Limited by number of
objects in a database
|
Limited by number of
objects in a database
|
|
Columns per UPDATE
statement (Wide Tables)
|
4096
|
4096
|
|
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 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. 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,
you can include nonkey columns in a nonclustered index to avoid the maximum
index key size of 900 bytes.
|
|
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 64
databases, or more than 2 databases in interleaving, you will receive an
error.
|
|
8SQL Server 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 Books Online.
|
