DBMS Connector Limits

Each database can impose restrictions on the size, number or length of tables, records, fields, keys, and indexes.

For the most accurate information for your database and version, consult the respective DBMS documentation.

In the following table, all lengths are in bytes, unless otherwise indicated.

Connector Limits
Connector Record Length Fields per Record Fields per Key Number of Indexes Key Length Field Length Row Length Field & Table Name Length
DB2 1 32,677 1012 16         30
Informix OL 32,511   16 100 51114 32,511   18
Informix SE 32,511   8 100 120 32,511   18
MS SQL Server 8000 2 or 20 MB 3 1024 16 249 900 80604 1800 or 80005 30 or 1286
MySQL7                

Oracle

8192 or 2GB-18 1000 16 Unlimited 8192 Varies 9    
PostgreSQL 7

 

 

 

 

 

 

 

 
Sequential 8192 N/A N/A N/A N/A      
SQLite 11 8192 or 2GB-1 8 2000 N/A Unlimited 109 109 109 109
Sybase 1800 12 250 16 250 255 8000 13    
Text 8192 or 2GB-18        

 

    
  1. Additional restrictions apply. For more information, see DB2 Limits.
  2. When using overflow tables, or 4000 bytes when nls is also enabled. For more information, see .
  3. The maximum record length for SQL Server is 20 MB, without the Uniface overflow mechanism, or 10 MB when nls is enabled.

    If every field in a record is a VARCHAR and contains all 8000 bytes, then the maximum record length is (8060/3) * 8000 = 21488000 bytes. Values for the connector option record size above 8000 will be ignored. For more information, see record size.

    For more information, consult the SQL Server documentation: Maximum Capacity Specifications for SQL Server and documented limitations in Row-Overflow Data Exceeding 8 KB .

  4. 4000 when nls is enabled. For more information, see .

  5. 1800 with mapping setting 1.

    8000 with mapping setting 2, or 4000 if nls is also enabled. For more information, see .

  6. 30 with mapping setting 1, 128 with mapping setting 2.
  7. See your database documentation.
  8. This database does not have a record size limit, so the connector imposes one. For entities with unlimited variable length fields (C*, VC*), the limit is 8KB. For entities with only fixed length fields the maximum record size is 2GB-1. For more information, see Variable-Length Packing Codes.
  9. The maximum field length depends on the storage format.
  10. 32 KB (UTF8) for fixed part of records containing Uniface variable length fields. Unlimited for records without Uniface variable length fields.
  11. For more information, see the SQLite documentation: https://sqlite.org/limits.html.
  12. The Sybase record limit is configurable. For more information, see row limit.
  13. Except Text and Image.
  14. To use the maximum key length of 511, the page size used by the database needs to be at least 4K.