Difference Between 2k, 4k, 8k, 16k Logical Page Size in SAP ASE

The main difference between a 2K, 4K, 8K, 16K page size is the amount of data stored on it. The larger the page, the more rows you can pack on it. This in turn translates into more rows brought into memory with each disk I/O.

If you are migrating from a larger page size to a lower page size, it typically means you did not research the topic, started with a large page size, and are wasting memory with each I/O, bringing more rows into memory than you are using.

Typically large page sizes benefit DSS (Decision Support System) applications, where you really want to operate on all the rows that you are bringing into memory with each I/O, so they are really not suitable for OLTP (On Line Transactional Processing) environments. Typically smaller page sizes benefit OLTP applications, where you might bring a single page into memory only to process one row.

If you are migrating from a lower page size to a larger page size, it typically means that you are you may have a mixed OLTP and DSS environment.

The following steps can be taken to check the page size:
1. Log into the SAP ASE server as the database user.
2. Run the following SQL statement:
1>SELECT @@maxpagesize
2>go

The value of the maximum page size will be displayed.