Home
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 backup and restoreFour configuration parameters that affect backup and restore on all operating systems also affect background I/O. Additional configuration parameters affect backup and restore on UNIX™.
ON-Bar configuration parametersBAR_MAX_BACKUP, BAR_NB_XPORT_COUNT, BAR_PROGRESS_FREQ, and BAR_XFER_BUF_SIZE are some ON-Bar configuration parameters that affect background I/O.

ON-Bar configuration parameters

BAR_MAX_BACKUP, BAR_NB_XPORT_COUNT, BAR_PROGRESS_FREQ, and BAR_XFER_BUF_SIZE are some ON-Bar configuration parameters that affect background I/O.

The BAR_MAX_BACKUP configuration parameter specifies the maximum number of backup processes per ON-Bar command. This configuration parameter also defines the degree of parallelism, determining how many processes start to run concurrently, including processes for backing up and restoring a whole system. When the number of running processes is reached, further processes start only when a running process completes its operation.

BAR_NB_XPORT_COUNT specifies the number of shared-memory data buffers for each backup or restore process.

BAR_PROGRESS_FREQ specifies, in minutes, how frequently the backup or restore progress messages display in the activity log.

BAR_XFER_BUF_SIZE specifies the size, in pages, of the buffers.