LOGSCAN scan range definition
This syntax determines the part of the Db2 log that Log Master scans for log records. It also enables you to specify the start point for REDO information (often called a recovery point).
shows the Scan range definition syntax of the LOGSCAN statement.
If you specify the REPOS DELETE keyword of the LOGSCAN statement, the Scan range definition is not required.
|FROM Range definition TO Range definition|
Specifies the portion of the Db2 log that Log Master scans (also called the time frame). FROM indicates the start point and TO indicates the end point of the log scan. Each Range definition defines one point in the Db2 log. For more information, see Range definition.
Defines an alternate limit on the range of the log scan. When you specify this keyword, the end point of your log scan is the point defined by the TO keyword in the Range Definition or the point defined by OR LIMIT, whichever comes first. The default value of this keyword does not define an alternate limit.
This keyword is frequently used with ongoing jobs. For example, assume that during a period of high logging activity, an ongoing job does not complete during its assigned processing window. The operating system terminates the job. No valid output is produced. If you run the job again, the same problem exists. In this situation, define an alternate limit that includes a range of log short enough to be processed by Log Master during the window. You can then run the same job repeatedly (producing valid output for each run without changing SYSIN syntax for each run), until you work your way through the period of high activity and 'catch up' to normal operation.
The limit defined by this keyword does not define how long Log Master executes at runtime; it defines only how much log Log Master scans. For example, if you specify
Be aware of the following points when specifying an alternate limit:
Determines the start point that Log Master uses to generate REDO information. This point is also referred to as the recovery point or point of recovery. Log Master can write REDO information to a logical log file, an SQL output file (in the form of REDO SQL), or a report (in one of three report formats).
Use REDO information to re-apply a set of transactions after a recovery action, while omitting a set of 'problem' transactions defined by your Range definition and WHERE clause. For more information, see REDO.
To generate REDO information, define a recovery point and a WHERE clause that refers to at least one specific Db2 object (such as a table space, table, or column). BMC Software strongly recommends that you generate REDO SQL before you recover any table spaces. You might be able to generate the SQL statements after the recovery by using the PROCESS PITS keyword of the OPTION statement, but BMC Software does not recommend doing so. For more information, see PROCESS PITS.
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