The 'read ahead' quality could be better (parameter RA_PAGES too big?)

What causes this issue?

This is a single 'performance' check and therefore does not
describe a critical system status. It is neither necessary nor
time-critical to perform the steps described below, but they could
help improve the overall performance of your R/3 System.

The system issues an error message and will not allow you to continue with this transaction until the error is resolved.

The quality of the Informix feature 'Read ahead' (percent ratio
between pages read as a preventive measure and pages actually used
in the database buffer) is not very good. The reason for this could
be that the ONCONFIG parameter 'RA_PAGES' is configured too large.
'RA-PAGES' specifies the number of pages to be read as a preventive
measure. If this value is constantly too large, the displacement
in the buffer will be too large. Only configure a 'realistic'
value for 'RA_PAGES'.
Also read Note 41360 (parameter 'RA_PAGES') about this topic.

System Response

How to fix this error?

To change an ONCONFIG parameter, edit file
'$INFORMIXDIR/etc/$ONCONFIG'. as user 'informix'.
CAUTION: The change will only become active after starting up the
database.

Error message extract from SAP system. Copyright SAP SE.