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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™.
Disk, memory, and process management
Shared memoryThese topics describe the content of database server shared memory, the factors that determine the sizes of shared-memory areas, and how data moves into and out of shared memory.
Flush data to diskWriting a buffer to disk is called buffer flushing.
Flush before-images firstThe before-images of modified pages are flushed to disk before the modified pages themselves.

Flush before-images first

The before-images of modified pages are flushed to disk before the modified pages themselves.

In practice, the physical-log buffer is flushed first and then the buffers that contain modified pages. Therefore, even when a shared-memory buffer page must be flushed because a user thread is trying to acquire a buffer but none is available (a foreground write), the buffer pages cannot be flushed until the before-image of the page has been written to disk.