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AdministeringIn addition to administering the database server, you can tune performance, replicate data, and archive data.
System administrationThese topics contain concepts, procedures, and reference information for database and database server administrators to use for managing and tuning HCL OneDB™ database servers.
Administrator's GuideThe HCL OneDB™ Administrator's Guide provides the information required to administer HCL OneDB™.
Logging and log administration
Manage logical-log files
Allocate logical log filesWhen you initialize or restart the database server, it creates the number of logical-log files that are specified by the LOGFILES configuration parameter. The size of the logical log files is specified by the LOGSIZE configuration parameter.
Dynamically add a logical-log file to prevent transaction blockingThe DYNAMIC_LOGS configuration parameter determines when the database server dynamically adds a logical-log file to prevent transaction blocking.
Size and number of dynamically added log filesThe purpose of enabling dynamic logs with the DYNAMIC_LOGS configuration parameter is to add enough log space to allow transactions to roll back.

Size and number of dynamically added log files

The purpose of enabling dynamic logs with the DYNAMIC_LOGS configuration parameter is to add enough log space to allow transactions to roll back.

When dynamically adding a log file, the database server uses the following factors to calculate the size of the log file:

Average log size
Amount of contiguous space available

If the logical log is low on space, the database server adds as many log files as necessary to allow the transaction to roll back. The number of log files is limited by:

The maximum number of log files supported
The amount of disk space for the log files
The amount of free contiguous space in the root chunk

If the database server stops adding new log files because it is out of disk space, it writes an error message and sets off an alarm. Add a dbspace or chunk to an existing dbspace. Then the database server automatically resumes processing the transaction.

The reserve pages in the root chunk store information about each log file. The extents that contain this information expand as more log files are added. The root chunk requires two extents of 1.4 megabytes each to track 32,767 log files, the maximum number supported.

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