PAGESIZE

onconfig.std
value

4096

if not present

4096

units

Bytes

range of values

2048, 4096, or 8192

takes effect

When the database server is initialized

refer to

The following material:

• Chapter on managing disk space in the IBM Informix: Administrator's Guide
• Your IBM Informix: Performance Guide
• IBM Informix: Migration Guide

When you install Extended Parallel Server, use PAGESIZE to configure the database server page size. You can specify a page size of 2048, 4096, or 8192 bytes. If you do not set the PAGESIZE parameter, the database server uses the default page size of 4096 bytes. Once you set the PAGESIZE value, you cannot change it without reinitializing the database server.

Use the following chart to select the best page size for your database server. If your workload is mostly DSS queries, a larger page size provides better performance. If your workload is mostly OLTP, a smaller page size provides better performance.

Workload Type

PAGESIZE Value

OLTP

2048 bytes

Mixture of OLTP and
DSS (50%-50%)

4096 bytes

DSS

8192 bytes

Many simple large objects or
long rows

8192 bytes

To check the page size, use the onstat -b or onutil CHECK RESERVED utility.