Database changes target weekend's quiet
June 22, 2012
The HP 3000s still serving throughout the world are often on all-day, every day duty. But activity can quiet down on the weekends. That's when Terry Simpkins, Director of Business Systems at the manufacturer Measurement Specialties, wanted to add an index.
"I need to add a new index into a detail dataset," he said. "But I'd like to complete this change on Sunday, if possible, while there are no users on the system." Simpkins hoped that DBGeneral would be able to adjust a Jumbo dataset in IMAGE, but a problem cropped up that didn't have an immediate weekend solution using that Bradmark tool in his IT belt.
The detail is a 'JUMBO'. The new index will be to a new Automatic master set. Using DBGeneral, I get an error when I attempt to 'activate' the change. It says the number of blocks exceeds the IMAGE max. The detail is very large. Is there some undocumented switch that needs to be specified for DBGeneral to work on JUMBO databases?
Whether DBGeneral has any undocumented Jumbo dataset switch didn't come up in users' replies to the issue. But Sunday support expectations, and the built-in nature of the alternative tool to DBGeneral, Adager, rose up. Not even a better tool can enable a change to such a very large detail dataset, however.
"I think that you probably are exceeding the MPE file size on your detail dataset when DBGeneral tries to add the new index pointers," Pete Eggers said. "My choice would be Adager over DBGeneral years ago, and I suspect that would still be true. But even Adager cannot create datasets that exceed MPE's file size limit." But these are the instances when such advice helps teach about the limits which applications must respect in IMAGE/SQL, as well as the tools to work around them.
"If this is true, your only option is to either reduce the record count of the dataset first -- if for instance, you can send some of the records to a history dataset or file," Eggers added. "You might be able to split the detail dataset into two datasets to add the index to the one with the field in question, but that probably won't happen on a Sunday, as all apps that access the dataset will have to be modified."
Steve Cooper pointed out that a Sunday call to Adager's support line would be answered promptly, "even if it is early -- and they will take your order for a copy of Adager, which will have no problem dealing with Jumbo datasets, no hidden switches needed."
Wyell Grunwald, a veteran of more than two decades of 3000 management, echoed the praise for a database manager like Adager. At Measurement Specialites, an empire of 3000s around the world manage manufacturing operations. Grunwald added that the situation there "Sounds like a repack would be in order -- to remove all your logically deleted records."
Keeping a 3000 in production use as a homesteader is most responsible when tools like database managers remain available -- and their support teams are quickly contacted, even on weekend hours. Best of luck to managers who are using this less-critical time to improve and expand the reach of their 3000 data. It's easier with good tools.