CICS File Openstatus Enablestatus

 In CICS, the open status of a VSAM file can either be OPEN or CLOSED, and this is indicated by the OPENSTATUS attribute in the file entry in the CICS file control table. If CICS closes a file, it is also de-allocated so that it can be processed by batch jobs. A file also has an enabled status, indicated by the ENABLESTATUS attribute, which can be either ENABLED, DISABLED, or UNENABLED. The enabled status determines whether or not a CICS application program request to a VSAM file can be attempted. If a file is disabled or unenabled, CICS fails the application program request without even attempting to send the request to VSAM. If the file is enabled, CICS issues the VSAM request on behalf of the application program.

The following are the most common combinations of these two states:

OPEN, ENABLED

CLOSED, ENABLED

OPEN, DISABLED

CLOSED, DISABLED

CLOSED, UNENABLED

In the first case (OPEN, ENABLED), the file is open and available to CICS application programs and if a batch job tries to access the file, it generally fails.

In the second case (CLOSED, ENABLED), the file is closed and not allocated, but it is available to CICS programs. In this state, if your application program issues a file access request, CICS attempts to allocate then open the file. If CICS cannot allocate and open the file, it is most probably because it is allocated to a batch job, and the application program request fails. Also in this case, as long as the file is closed, it is available for access by batch jobs.

In the last three cases in the above list (OPEN, DISABLED; CLOSED, DISABLED; and CLOSED, UNENABLED), CICS fails all file control requests without even attempting them because the file is not enabled. The key difference in these three cases is that in one the file is open and in the other two it is closed. In the open case, it is allocated to CICS so that batch jobs that attempt to access the file will probably fail. In the closed cases , it is not allocated to CICS, and is available for access by batch jobs.

Note that when a file is closed to CICS, and therefore de-allocated, the file can even be deleted by a batch job.

For the most part, the DISABLED and UNENABLED states are the same. Both states prevent an application program from accessing the file. However, there is one important difference that you must take into consideration when changing the state of a file.

The only way that a file becomes unenabled is when you close the file without altering its enabled status. You can do this using the CICS BAC batch request utility, or by using the EXEC CICS SET FILE command or the CEMT SET FILE transaction. For example, if FILEA is currently open and enabled, and you issue the CEMT command SET FILE(FILEA) CLOSED, the resulting file attributes are set to CLOSED and UNENABLED. However, if the file is currently open and disabled, the same command results in the file state being set to CLOSED and DISABLED.

The difference between a disabled and an unenabled file is in how the file state is set when a closed file is subsequently opened. If a file is currently closed and disabled, and a request is made through the CICS BAC batch request utility, CICS system programming interface (SPI), or CICS CEMT command to open the file without altering its enable status attribute, the file is opened (assuming there is nothing to keep it from being opened), but its enable status remains DISABLED. On the other hand, if a file is unenabled, an open request that does not also specify an enabled status results in the file state being set to OPEN and ENABLED.

If you issue a request that alters the enable status of a file explicitly, the file ENABLESTATUS attribute is changed regardless of whether the current state is ENABLED, DISABLED, or UNENABLED.