MSSQL
This section provides details about the limitations for the MSSQL Server implementation.
By default, the RECID key column is created as a 255-character field. To use XML indexes, this field must be less than 128 characters. You can override the default field size with the KEY qualifier of the CREATE-FILE command. The XMLRECORD column can be a maximum of 2GB for both XML and BLOB types.
MSSQL Server Components
The following table lists the maximum sizes and numbers of various objects defined in MSSQL Server 2008R2 components.
|
SQL Server Database Engine Object |
Maximum size or number of SQL Servers (64-bit) |
|---|---|
|
Batch size1 |
65,536 * Network Packet Size |
|
Bytes per short string column |
8,000 |
|
Bytes per GROUP BY, ORDER BY |
8,060 |
|
Bytes per index key2 |
900 |
|
Bytes per foreign key |
900 |
|
Bytes per primary key |
900 |
|
Bytes per row8 |
8,060 |
|
Bytes in source text of a stored procedure |
Lesser of batch size or 250 MB |
|
Bytes per varchar(max), varbinary(max), xml, text, or image column |
2^31-1 |
|
Characters per ntext or nvarchar(max) column |
2^30-1 |
|
Clustered indexes per table |
1 |
|
Columns in GROUP BY, ORDER BY |
Limited only by number of bytes |
|
Columns or expressions in a GROUP BY WITH CUBE or WITH ROLLUP statement |
10 |
|
Columns per index key7 |
16 |
|
Columns per foreign key |
16 |
|
Columns per primary key |
16 |
|
Columns per non-wide table |
1,024 |
|
Columns per wide table |
30,000 |
|
Columns per SELECT statement |
4,096 |
|
Columns per INSERT statement |
4096 |
|
Connections per client |
Maximum value of the configured connections |
|
Database size |
524,272 terabytes |
|
Databases per instance of SQL Server |
32,767 |
|
Filegroups per database |
32,767 |
|
Files per database |
32,767 |
|
File size (data) |
16 terabytes |
|
File size (log) |
2 terabytes |
|
Foreign key table references per table4 |
253 |
|
Identifier length (in characters) |
128 |
|
Instances per computer |
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 |
|
Locks per connection |
Maximum locks per server |
|
Locks per instance of SQL Server5 |
Limited only by memory |
|
Nested stored procedure levels6 |
32 |
|
Nested subqueries |
32 |
|
Nested trigger levels |
32 |
|
Non-clustered indexes per table |
999 |
|
Number of distinct expressions in the GROUP BY clause for CUBE, ROLLUP, GROUPING SETS, WITH CUBE, or WITH ROLLUP |
32 |
|
Number of grouping sets generated by operators in the GROUP BY clause |
4,096 |
|
Parameters per stored procedure |
2,100 |
|
Parameters per user-defined function |
2,100 |
|
REFERENCES per table |
253 |
|
Rows per table |
Limited by available storage |
|
Tables per database3 |
Limited by number of objects in a database |
|
Partitions per partitioned table or index |
1,000 |
|
Statistics on non-indexed columns |
30,000 |
|
Tables per SELECT statement |
Limited only by available resources |
|
Triggers per table3 |
Limited by number of objects in a database |
|
Columns per UPDATE statement (Wide Tables) |
4096 |
|
User connections |
32,767 |
|
XML indexes |
249 |
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