LOGBUFF

onconfig.std value

32

units

Kilobytes

range of values

32 kilobytes through (32767 * page size / 1024) kilobytes

takes effect

When the database server is shut down and restarted

utilities

onstat -l buffer field, second section (See page onstat -l.)

refer to

Logical-log buffer, in the shared-memory chapter of the IBM Informix Administrator's Guide

LOGBUFF specifies the size in kilobytes for the three logical-log buffers in shared memory. Triple buffering permits user threads to write to the active buffer while one of the other buffers is being flushed to disk. If flushing is not complete by the time the active buffer fills, the user thread begins writing to the third buffer.

It is recommended that you set LOGBUFF to 16 or 32 kilobytes, or perhaps 64 kilobytes for heavy workloads. Choose a value for LOGBUFF that is evenly divisible by the page size. If the value of LOGBUFF is not evenly divisible by the page size, the database server rounds down the size to the nearest value that is evenly divisible by the page size.

If you log user data in smart large objects, increase the size of the log buffer to make the system more efficient. The database server logs only the portion of a smart-large-object page that changed.

To set the system page size, use one of the utilities listed in System Page Size.