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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
Virtual processors and threadsThese topics describe virtual processors, explain how threads run within the virtual processors, and explain how the database server uses virtual processors and threads to improve performance.
Virtual processor classesEach class of virtual processor is dedicated to processing certain types of threads.
Disk I/O virtual processorsThe following classes of virtual processors perform disk I/O: PIO (physical-log I/O), LIO (logical-log I/O), AIO (asynchronous I/O), and CPU (kernel-asynchronous I/O).
Asynchronous I/OThe database server performs database I/O asynchronously, meaning that I/O is queued and performed independently of the thread that requests the I/O. Performing I/O asynchronously allows the thread that makes the request to continue working while the I/O is being performed.

Asynchronous I/O

The database server performs database I/O asynchronously, meaning that I/O is queued and performed independently of the thread that requests the I/O. Performing I/O asynchronously allows the thread that makes the request to continue working while the I/O is being performed.

The database server performs all database I/O asynchronously, using one of the following facilities:

AIO virtual processors
KAIO on platforms that support it

Database I/O includes I/O for SQL statements, read-ahead, page cleaning, and checkpoints.