Creating a change accumulation group
Each time you run a R+/CHANGE ACCUM batch job for a particular group, R+/CHANGE ACCUM generates a change accumulation file set.
The following figure shows the components of a change accumulation group:
Naming a change accumulation group
The name of a change accumulation group consists of 1 to 18 alphanumeric, national, or special ($, @, -, _, #) characters.
Specifying target object definitions
The following rules apply when specifying target objects:
- You can include a target object in more than one group.
- You can include any number of target objects in a group as long as a sufficient amount of REGION is specified on the EXEC statement when you run the batch utility.
- A group can include certain combinations of table spaces, partitions, and data sets.
- You cannot define indexes to a group through the repository. To accumulate index log records, specify the INDEXES YES option on the ACCUM statement.
- You cannot define cloned objects through the repository. To accumulate log records for clones, specify the CLONE option.
- The repository and the target objects that you select for a change accumulation group must reside on the same target Db2 subsystem.
Using wildcards
You can specify multiple databases and table spaces by using the ?, *, or % wildcard characters.
The ? character represents any single character that occurs in the designated position. The % or * characters represent zero or more characters in that position.
Specifying partitions or data sets
To specify a particular partition or data set for the change accumulation group, you must specify the DSNUM option.
For more information, see DSNUM. If the table space is partitioned, DSNUM cannot be greater than the number of partitions. If the table space is nonpartitioned table space, DSNUM cannot be greater than 32.
You can specify a range of DSNUMs.
To use all of the partitions for a partitioned table space, specify LODSNUM=0 and HIDSNUM=0.
The INDEXES YES option is available only when you specify ACCUM and the group includes all partitions.
Specifying file templates
The file templates determine how many copies of change accumulation files are generated for a group.
The following file templates are available:
- LOCAL PRIMARY
- LOCAL BACKUP
- REMOTE PRIMARY
- REMOTE BACKUP
The data set name pattern that you specify for each copy in the file set can be a maximum of 60 characters. You can specify data set names as a generation data group (GDG), or you can use symbolic variables.
Before creating the file set and reading log records, R+/CHANGE ACCUM checks the MVS catalog to ensure that the files do not already exist. If R+/CHANGE ACCUM finds any discrepancies, R+/CHANGE ACCUM issues an error message, and stops executing.
Using GDGs
To specify a GDG as the data set name, include (+1) at the end of the model for the data set name.
If you use a GDG, specify a different data set name model for each copy of the change accumulation file within the same change accumulation group. Each time you run R+/CHANGE ACCUM for the group, R+/CHANGE ACCUM increments by one the data set names for the change accumulation files.
Using symbolic variables
You can use symbolic variables to specify data set name patterns for the file set.
For more information, see the following table.
You must follow a symbolic variable with a period, ampersand (&), or any special character that is not alphanumeric and not $, @, or #. Further guidelines are as follows:
- Using a period terminates the symbolic variable. The generated data set name does not include the period.
- An ampersand indicates the beginning of another symbolic variable. The generated data set name does not include the ampersand.
- Trailing blanks are not included in any values for symbolic variables when R+/CHANGE ACCUM generates a change accumulation file name.
Symbolic variables used in data set names
Symbol | Result |
|---|---|
&CAFILE | A counter from one to four digits of change accumulation file sets that were created for a change accumulation group If duplicate copies are created (for example, LP and LB), R+/CHANGE ACCUM uses the same number for each copy. |
&CAGROUP &GROUP | Name of the change accumulation group If the name exceeds eight characters, R+/CHANGE ACCUM uses only the first eight characters. If the group name contains characters that are not allowed in a data set name, R+/CHANGE ACCUM eliminates these characters. |
&DATE | date of the R+/CHANGE ACCUM job run (in the form YYMMDD) |
&DAY | Current day (in the form DD) |
&DB | Database containing the space being copied |
&DSNUM, &PART | Data set or partition being copied
|
&HOUR | Current hour (in the form HH) |
&ICTYPE | Type of image copy:
|
&INST | Instance number, with valid values of 1 or 2 |
&JDATE | Current Julian date (in the form YYDDD) |
&JDAY | Current Julian day (in the form DDD) |
&JOBNAME &JOB | Job name that is used in the R+/CHANGE ACCUM job |
&LDSNUM, &LPART | Data set or partition being copied
|
&MINUTE | Current minute (in the form MM) |
&MONTH | Current month (in the form MM) |
&SECOND | Current second (in the form SS) |
&SEQ | A sequential number that restarts at 1 at the beginning of each job step execution |
&SP | Space name of the table or index being copied |
&STEPNAME &STEP | Step name that is used in the R+/CHANGE ACCUM job |
&SSID | DB2 subsystem ID that identifies where the repository resides |
&TIME | Time of the R+/CHANGE ACCUM job run (in the form HHMMSS) |
&TS | Table space or index space is copied |
&TYPE | Type of output file that is created:
|
&UTILID &UTIL | Name of the R+/CHANGE ACCUM utility ID If the name exceeds eight characters, R+/CHANGE ACCUM uses only the first eight characters. |
&USERID &UID | The user ID that is assigned to the R+/CHANGE ACCUM job |
&YEAR | Current year (in the form YY) |
In the following examples, the subsystem ID is DB2Y. In the first example, notice that &SSID is followed by a period. TEST.&SSIDWX would not be valid because &SSID is not terminated with a period.
When &SSID is followed by two periods, the first period terminates the symbolic variable, and the second period becomes part of the generated name.
The next example shows that a combination of symbolic variables is valid if the combined values do not exceed eight characters. In this example, the subsystem ID is still DB2Y and the user ID is ABC.
Limitations when used with BMC AMI Recover
The ACCUM command is not valid in the same SYSIN with the following BMC AMI Recover commands and options:
- LOGSCAN command
OPTIONS SIMULATE YES option
For the recovery simulation feature, the output of change accumulation files is not supported. (However, the use of change accumulation files as input to recovery simulation is supported.)
A recovery that uses the BACKOUT option does not use logs from the change accumulation files. A BACKOUT recovery uses only the regular Db2 logs.