RE: [MI400] What is main memory resident?

["Paul Godtland" <plg@xxxxxxxxxx>]

Kaare Plesner wrote:
|"if turned on, QPFRADJ may move pages between pools" still does NOT
|apply for private pools??

Correct. The automatic performance adjustment features will not change the
size of private memory pools. Thanks to you and others for seeking
clarification of my overly-general earlier statement on performance
adjustment.

Leif Svalgaard wrote:
|I  think the presumption is
|that the "bring" can be done many pages at a time.

Also true. A single i/o operation can involve many main store pages. Of
course, the system database code will attempt to limit i/o operations, too,
so one can't assume that manual controls of paging will always reduce i/o
operations. Similarly, database algorithms change over time, so one must
understand that manual paging control that is helpful at one point may not
necessarily be beneficial in the future.

Anticipating follow-up questions: :-) I don't think the current maximum i/o
numbers are externally published because they are model-dependent and so
can change over time, so I don't plan to go into more detail about them
here.

I recommend the IBM Info Center for more information. For example, see
http://publib.boulder.ibm.com/html/as400/v5r1/ic2924/index.htm, in
particular the Performance and Work Management sections.

Paul Godtland