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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.
Performance GuideThe HCL OneDB™ Performance Guide describes how to configure and operate your HCL OneDB™ database server to improve overall system throughput and to improve the performance of SQL queries.
Effect of configuration on I/O activityThe configuration of your database server affects I/O activity.
Background I/O activitiesBackground I/O activities do not service SQL requests directly. Many of these activities are essential to maintain database consistency and other aspects of database server operation. However, they create overhead in the CPU and take up I/O bandwidth.
Configuration parameters that affect loggingThe LOGBUFF, PHYSBUFF, LOGFILES, LOGSIZE, DYNAMIC_LOGS, AUTO_LLOG, LTXHWM, LTXEHWM, SESSION_LIMIT_LOGSPACE, SESSION_LIMIT_TXN_TIME, and TEMPTAB_NOLOG configuration parameters affect logging. The LOGBUFF, PHYSBUFF, LOGFILES, LOGSIZE, DYNAMIC_LOGS, LTXHWM, LTXEHWM, and TEMPTAB_NOLOG configuration parameters affect logging.
LOGSIZE and its effect on loggingThe LOGSIZE configuration parameter specifies the size of each logical log file. It is difficult to predict how much logical-log space your database server system requires until the system is fully in use.
Estimating the logical-log size when logging smart large objectsIf you plan to log smart-large-object user data, you must ensure that the log size is considerably larger than the amount of data being written. Smart-large-object metadata is always logged even if the smart large objects are not logged.

Estimating the logical-log size when logging smart large objects

If you plan to log smart-large-object user data, you must ensure that the log size is considerably larger than the amount of data being written. Smart-large-object metadata is always logged even if the smart large objects are not logged.

Use the following guidelines when you log smart large objects:

If you are appending data to a smart large object, the increased logging activity is roughly equal to the amount of data written to the smart large object.
If you are updating a smart large object (overwriting data), the increased logging activity is roughly twice the amount of data written to the smart large object. The database server logs both the before-image and after-image of a smart large object for update transactions. When updating the smart large objects, the database server logs only the updated parts of the before and after image.
Metadata updates affect logging less. Even though metadata is always logged, the number of bytes logged is usually much smaller than the smart large objects.

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