RE: Accessing a file in memory

[Chris Bipes <chris.bipes@xxxxxxxxxxxxxxx>]

If this file has only a few records, load it at init to a table.  The first
field in the table is the unique key.  The second is the length of the
entire record format.  I use an externally described DS and move the second
field to the DS to get the record layout.

Another solution, if you have amble memory, is to create a memory partition
large enough to hold the entire file.  Then a small program reads the entire
file and goes into a wait.  If this is the only job run in the memory
partition, it will remain cashed in memory.  Other jobs will take advantage
of this.

Yet another way is to load  the file into a keyed data queue and use the
message peek to retrieve the record without removing it.

If the application will allow, presort the master file by the key of the aux
file and only read the aux file at level break.

We use a mixture of all.  What I have not tried is a user space, but that is
another possibility.

Hope this gets you think-in.



Christopher K. Bipes     mailto:ChrisB@Cross-Check.com
Sr. Programmer/Analyst   mailto:Chris_Bipes@Yahoo.com
CrossCheck, Inc.         http://www.cross-check.com
6119 State Farm Drive    Phone: 707 586-0551 x 1102
Rohnert Park CA  94928 Fax: 707 586-1884

If consistency is the hobgoblin of little minds, only geniuses work here.
Karen Herbelin - Readers Digest 3/2000


-----Original Message-----
From: Contractor1@parkdalemills.com
[mailto:Contractor1@parkdalemills.com]
Sent: Monday, July 17, 2000 10:17 AM
To: RPG400-L@midrange.com
Subject: Accessing a file in memory



We have a project where a few files are accessed a lot in a job stream and
the job takes over an hour to run. We are looking for ways to speed up the
process. We are wanting to load the few files into memory rather than
accessing the files off the disk because we heard that a company that
purchased the same software did the same. Can you advise us on what might
be the best solution? User space, what?

Thank you,

Patrick Conner
www.ConnecTown.com
(828) 244-0822
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