Database Integrity Support
Database integrity support includes referential integrity checking, locking, and transaction control, including two-phase commit. The type and degree of support for these features varies with the database.
By default, Uniface handles referential integrity checking. For some databases, it is possible for the database itself to handle referential integrity, in which case a connector option disables or enables Uniface referential integrity. The name of this option is DBMS-specific and the default state depends on the DBMS connector used.
Uniface locking is supported for most databases, but some restrictions or special considerations may apply. DBMSs vary in their locking behavior (optimistic locking might be the DBMS default, or different locking strategies are applied in different circumstances).
Uniface transactions can be explicitly defined with the commit and rollback ProcScript commands, which are supported by most databases. Support for two-phase commit varies and other transaction control issues may apply.
For more information, see Referential Integrity, Locking Strategies, and Transaction Control .
|
Connector |
DBMS Referential Integrity? |
Locking? |
Commit/Rollback? |
Two-Phase Commit? |
Details |
|---|---|---|---|---|---|
|
DB2 |
Yes |
Yes |
Yes |
No |
For more information, see Referential Integrity Management for DB2, Locking Support on DB2 and Commit/Rollback Support on DB2 . |
|
Informix |
Yes |
Yes |
Yes |
Yes |
For more information, see Locking Support on Informix and Transaction Control on Informix. |
|
MS-SQL Server |
Yes |
Yes |
Yes |
No |
For more information, see Locking Support on Microsoft SQL Server and Transaction Control on Microsoft SQL Server. |
|
MySQL |
No |
Yes |
Yes |
No |
For more information, see Referential Integrity Management on MySQL. |
|
ODBC |
No |
Yes |
Yes |
No |
For more information, see Referential Integrity Management on ODBC. |
|
Oracle |
No |
Yes |
Yes |
No |
|
|
PostgreSQL |
Yes |
Yes |
Yes |
No |
For more information, see Data Integrity on PostgreSQL. |
|
Sequential |
No |
No |
No |
No |
For more information, see Database Integrity Support on SEQ. |
|
SQLite |
No |
Yes |
Yes |
No |
For more information, see Locking Considerations for SQLite. |
|
Sybase |
Yes |
Yes |
Yes |
No |
For more information, see Locking Support on Sybase and Transaction Control on Sybase. |
|
TXT |
No |
No |
No |
No |
|
Connector |
Must be contiguous |
May overlap |
Primary key mandatory 1 |
Candidate keys mandatory |
|---|---|---|---|---|
|
DB2 |
No |
Yes |
||
|
Informix |
No |
Yes |
No |
|
|
MS-SQL Server |
Yes |
No |
No |
|
|
MySQL |
No |
Yes |
No |
No |
|
ODBC 2 |
— |
— |
— |
— |
|
Oracle |
No |
Yes |
No |
No |
|
PostgreSQL |
||||
|
Sequential |
No |
Yes |
No |
No |
|
SQLite |
No |
Yes |
No |
N/A |
|
Sybase |
||||
|
Text |
No |
Yes |
No |
|
|
Notes:
|
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