IBM 000-8697 User Manual

IBM Informix OnLine Database Server Administrator’s Guide

If the value of

Pages/IO

 is 75 percent or more of

Bufsize

, each write to the

disk is, on average, deferred until the buffer is almost full. (Since the value of

Pages/IO

 is an average, some writes might be closer to 100 percent of the

buffer. The logging status affects this value; see the preceding paragraph.)

In this case, you can try to further improve buffer efficiency by increasing the
size of the buffer to accommodate more data before each write.

If the value of

Pages/IO

is less than 75 percent of

Bufsize

, writes to the disk

occur, on average, long before the buffer is fully used. In this case, you can try
to improve buffer efficiency by decreasing the size of the buffer to more
closely approximate the size of

Pages/IO

. Decreasing the size of the buffer

frees shared-memory space for other uses.

Refer to

for further information about how to change the size of the

logical log or physical log buffer.