The C3 command writes a SYNX-03 checkpoint in the Adabas checkpoint file.
This document covers the following topics:
The C3 command may be issued only by exclusive control/update users (who are not using ET logic).
The primary function of the C3 command is to write a SYNX-03 checkpoint in the Adabas checkpoint file. This checkpoint entry
contains the current data protection log and block number.
may be used to restore the database (or certain files) to the status in effect at the time the checkpoint was taken. This may be necessary before a program performing exclusive control updating can be rerun or restarted.
If command option 2 is specified, the C3 command also stores user data in the Adabas checkpoint file for restart purposes. The stored data may be subsequently read with an OP or RE command.
| Field | Position | Format | Before Adabas Call | After Adabas Call |
|---|---|---|---|---|
| 1-2 | -- | -- | -- | |
| COMMAND CODE | 3-4 | alphanumeric | F | U |
| 5-8 | -- | -- | -- | |
| FILE NUMBER** | 9-10 | binary | F | U |
| RESPONSE CODE | 11-12 | binary | -- | A |
| 13-26 | -- | -- | -- | |
| RECORD BUFFER LENGTH | 27-28 | binary | F | U |
| 29-35 | -- | -- | -- | |
| COMMAND OPTION 2 | 36 | alphanumeric | F | U |
| 37-72 | -- | -- | -- | |
| COMMAND TIME | 73-76 | binary | -- | A |
| USER AREA | 77-80 | -- | -- | U |
| Buffer | Before Adabas Call | After Adabas Call |
|---|---|---|
| FORMAT BUFFER | * | |
| RECORD BUFFER | F | U |
where:
| F | Filled in by user before Adabas Call |
| A | Filled in by Adabas |
| U | Unchanged after Adabas call |
| * | Not used but must be included in parameter list of call statement |
| ** | A database ID is only necessary if you are accessing multiple databases and need to limit the command operation to a specific database. |
| -- | Not used |
C3
A database ID is only necessary if you are accessing multiple databases and need to limit the command operation to a specific database.
Adabas returns the response code for the command in this field. Response code 0 indicates that the command was executed successfully.
Response codes and their subcodes are defined in the Adabas Messages and Codes documentation.
This field is used only if command option 2 is specified.
The number of bytes of user data to be stored must be specified in this field.
The maximum length that may be specified is 2000 bytes.
| Option | Description |
|---|---|
| E | indicates that user data is to be stored in the Adabas checkpoint file when the session terminates. This option is only available if the user provided a non-blank, unique user ID during the OP command for the user session. |
The record buffer contains the user data to be stored in the Adabas checkpoint file. The number of bytes actually stored is determined by the value specified in the record buffer length field.
The user data is retained only if the user issued an OP command for the user session in which a non-blank, unique user ID was provided. The data is retained until the next C3 or CL command issued by this user in which user data is provided. If a non-blank, unique user ID was not provided, the data cannot be retrieved in a subsequent session.
The user program issues a C3 command and provides user data to be stored in the Adabas checkpoint file.
| Command Code | C3 | |
|---|---|---|
| Record Buffer Length | 17 | 17 bytes of user data to be stored |
| Command Option 2 | E | user data are to be stored |
| Record Buffer | EXU-USER ET-DATA |
|---|
