This table specifies the maximum sizes and numbers of various objects defined in Microsoft® SQL Server™ databases, or referenced in Transact-SQL statements.
| Maximum sizes/numbers | ||
|---|---|---|
| Object | SQL Server 6.5 | SQL Server 7.0 |
| Batch size | 128 KB | 65,536* Network Packet Size |
| Bytes per short string column | 255 | 8000 |
| Bytes per text, ntext, or image column | 2 GB-2 | 2 GB-2 |
| Bytes per GROUP BY, ORDER BY | 900 | 8060 |
| Bytes per index | 900 | 900 |
| Bytes per foreign key | 900 | 900 |
| Bytes per primary key | 900 | 900 |
| Bytes per row | 1962 | 8060 |
| Bytes in source text of a stored procedure | 65025 | Lesser of batch size or 250 MB |
| Clustered indexes per table | 1 | 1 |
| Columns in GROUP BY, ORDER BY | 16 | Limited only by number of bytes |
| Columns or expressions in a GROUP BY WITH CUBE or WITH ROLLUP statement | 10 | 10 |
| Columns per index | 16 | 16 |
| Columns per foreign key | 16 | 16 |
| Columns per primary key | 16 | 16 |
| Columns per base table | 250 | 1024 |
| Columns per SELECT statement | 4096 | 4096 |
| Columns per INSERT statement | 250 | 1024 |
| Connections per client | Max. value of configured connections | Max. value of configured connections |
| Database size | 1 TB | 1,048,516 TB |
| Databases per server | 32,767 | 32,767 |
| Filegroups per database | N/A | 256 |
| Files per database | 32 | 32,767 |
| File size (data) | 32 GB | 32 TB |
| File size (log) | 32 GB | 4 TB |
| Foreign key table references per table | 16 | 253 |
| Identifier length (in characters) | 30 | 128 |
| Locks per connection | Max. locks per server | Max. locks per server |
| Locks per server | 2,147,483,647 | 2,147,483,647 (static) 40% of SQL Server memory (dynamic) |
| Nested stored procedure levels | 16 | 32 |
| Nested subqueries | 16 | 32 |
| Nested trigger levels | 16 | 32 |
| Nonclustered indexes per table | 249 | 249 |
| Objects concurrently open in a server* | 2 billion | 2,147,483,647 |
| Objects in a database* | 2 billion | 2,147,483,647 |
| Parameters per stored procedure | 255 | 1024 |
| REFERENCES per table | 31 | 63 |
| Rows per table | Limited by available storage | Limited by available storage |
| SQL string length (batch size) | 128 KB | 128* TDS packet size |
| Tables per database | 2 billion | Limited by number of objects in a database |
| Tables per SELECT statement | 16 | 256 |
| Triggers per table | 3 | Limited by number of objects in a database |
| UNIQUE indexes or constraints per table | 249 | 249 nonclustered and 1 clustered |
| * Database objects include all tables, views, stored procedures, extended stored procedures, triggers, rules, defaults, and constraints. The sum of the number of all these objects in a database cannot exceed 2,147,483,647. | ||