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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.
Database server thread access to shared buffersDatabase server threads access shared buffers through a system of queues, using mutexes and locks to synchronize access and protect data.
FIFO/LRU queuesA buffer holds data for the purpose of caching. The database server uses the least-recently used (LRU) queues to replace the cached data. HCL OneDB™ also has a first-in first-out (FIFO) queue. When you set the number of LRU queues, you are actually setting the number of FIFO/LRU queues.
Pages in least-recently used orderWhen the database server processes a request to read a page from disk, it must decide which page to replace in memory.

Pages in least-recently used order

When the database server processes a request to read a page from disk, it must decide which page to replace in memory.

Rather than select a page randomly, the database server assumes that recently referenced pages are more likely to be referenced in the future than pages that it has not referenced for some time. Thus, rather than replacing a recently accessed page, the database server replaces a least-recently accessed page. By maintaining pages in least-recently to most-recently used order, the database server can easily locate the least-recently used pages in memory.