On Wed, 9 Mar 2016 08:12:18 -0800, Ed Jaffe wrote: >On 3/8/2016 9:59 PM, Jesse 1 Robinson wrote: >> -- A data base application was redesigned at the last minute to read the >> entire data base into memory at startup. The business unit noticed that they >> were charged for I/O but not for memory use. It was cheaper to occupy >> virtual storage than to perform reads. So much for common sense. > >They were obviously ahead of their time! These days, memory-mapped files >are highly encouraged as one way to utilize that "free" memory everyone >is getting on their z13! > Decades ago, I knew a site with a chargeback formula in which average memory use was a factor. But the formula was such that adding a job step that ran a counter loop at minimal memory could decrease the total charge for the job. And I knew a parsimonious programmer who routinely exploited this. And that site charged for disk storage by a daily audit at 0300 so he dumped all his files to tape at 1800 and restored them at 0600.
Storage was more expensive back then. -- gil ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: INFO IBM-MAIN
