At 12:00 PM 8/8/2000 -0500, Jean Huot wrote:
>   Recently, I had the opportunity  to talk to Patrick at Adager.  I
> mentionned to him that our system was I/O bottleneck primarily because we
> updated credit cards randomly for a given tape supplier, one supplier at
> a time e.g GMAC.  He explained that when updating through an image key
> access, each trade line retrieval  from the database was picked up from a
> 4096 byte page access.  Also each trade line update was 1 io.  Since the
> access was random for a particular client supplier, say GMAC, then the
> system frequently had to dump what was in memory and read back from disk
> for the next update.
>
>Since I was updating a series of credit cards from one tape supplier from
>a flat file, then if a could preload all the GMAC accounts into memory,
>then very few access would be made to disk.

Old batch (is a bitch) technique:
Since you have a flat file anyway, why not simply sort it (on supplier)
prior to doing the update?

Brian Duncombe  [log in to unmask]  http://www.triolet.com
voice: 1-877-TRIOLET (874-6538) (905)632-2773 fax: (905) 632-8704
"Inside every large program is a small one struggling to get out"
C.A.R. Hoare