A cursor file is a DBH-specific work file that is required for processing retrieval statements.
Cursor files can have two meanings in SESAM/SQL:
on the one hand, SESAM/SQL-DBH stores the intermediate results of retrieval statements in cursor files.
on the other hand, multiple users can also store the results of CALL DML search queries in a cursor file and subsequently further restrict them. Such CALL DML-specific cursor files are identified by a file identifier (see the “CALL-DM Applications” manual).
Storage information pertaining to the internal cursor files is contained in the DBH's media catalog.
SESAM/SQL creates a maximum of two cursor files. The internal cursor files have the following standard names:
DBH variant | Standard name |
independent DBH | SESAMcn.CURSOR.0001 |
SESAMcn.CURSOR.0002 | |
linked-in DBH | SESLKcn.CURSOR.0001 |
SESLKcn.CURSOR.0002 |
Table 55: Standard names for internal cursor files
The final results of CALL DML search queries and of SQL statements referring to a cursor are stored in the file with the suffix “0001”. In addition, this file can be used as required as an internal temporary work area for storing intermediate results.
The intermediate results of secondary index analyses for CALL DML and SQL retrieval statements are stored in the file with the suffix “0002”.
Both files are created only if actually required.
Additional information on naming conventions, the default assignment and the access method associated with the “internal” cursor files is provided in the table “DBH-specific files”.