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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.
Factors that affect I/O for smart large objectsAn sbspace is a logical storage unit, composed of one or more chunks, in which you can store smart large objects (such as BLOB, CLOB, or multi representational data). Disk layout for sbspaces, the settings of certain configuration parameters, and some onspaces utility options affect I/O for smart large objects.
onspaces options that affect sbspace I/OWhen you create an sbspace with the onspaces utility, you specify information that affects I/O performance. This information includes the size of extents, the buffering mode (and whether you want the server to use lightweight I/O), and logging.
Lightweight I/O for smart large objectsInstead of using the buffer pool, the administrator and programmer have the option to use lightweight I/O. Lightweight I/O operations use private buffers in the session pool of the virtual portion of shared memory.
Advantages of lightweight I/O for smart large objectsLightweight I/O provides some performance advantages, because the database server is not using the buffer pool.

Advantages of lightweight I/O for smart large objects

Lightweight I/O provides some performance advantages, because the database server is not using the buffer pool.

Lightweight I/O provides the following advantages:

Transfers larger blocks of data in one I/O operation
These I/O blocks can be as large as 60 kilobytes. But the bytes must be adjacent for the database server to transfer them in a single I/O operation.
Bypasses the overhead of the buffer pool when many pages are read
Prevents frequently accessed pages from being forced out of the buffer pool when many sequential pages are read for smart large objects

When you use lightweight I/O buffers for smart large objects, the database server might read several pages with one I/O operation. A single I/O operation reads in several smart-large-object pages, up to the size of an extent. For information about when to specify extent size, see Sbspace extents.