At 20:08 10/22/1999 , you wrote: > > Views are unkeyed logical files.... > > >Huh? Now I'm confused... There's no -point- in having and unkeyed logical. > >The Key is the index sequence. Gotta have one. Au Contraire. The VIEW is very useful, but only for manipulating data with SQL. INDEXes provide the access paths. They can only be attached to a physical file. SQL will examine the WHERE, JOIN and ORDER BY clauses in your query, and select the appropriate access path (index), or build a temporary one if necessary. A VIEW describes data elements, where the data comes from, what transformations are to be performed on it when it is retrieved, and what relationships are required with literals or other column values. A VIEW can be based on one or more physical files or other views, and can contain grouping functions such as SUM, MAX and MIN, as well as calculations, conditional expressions and special register values like USER, CURRENT DATE and CURRENT TIME. It's even possible to build a pivot table as a view of transactional data and have it perform reasonably well. You can do lots of really slick stuff that a few years ago would have required a work file and a HLL program. Pete Hall firstname.lastname@example.org http://www.execpc.com/~pbhall +--- | This is the Midrange System Mailing List! | To submit a new message, send your mail to MIDRANGE-L@midrange.com. | To subscribe to this list send email to MIDRANGE-L-SUB@midrange.com. | To unsubscribe from this list send email to MIDRANGE-L-UNSUB@midrange.com. | Questions should be directed to the list owner/operator: email@example.com +---
As an Amazon Associate we earn from qualifying purchases.
Operating expenses for this site are earned using the Amazon Associate program and Google Adsense.