Browse Prior Art Database

Get Condition

IP.com Disclosure Number: IPCOM000077711D
Original Publication Date: 1972-Sep-01
Included in the Prior Art Database: 2005-Feb-25
Document File: 2 page(s) / 13K

Publishing Venue

IBM

Related People

Kendall, RC: AUTHOR

Abstract

The herein described record management algorithm permits dynamic creation and retrieval of historical records by conditional "get" and "put" means. It is not possible to continue to record data in a fixed space indefinitely, so provision is made to return to the starting point and record new transactions over the previously written ledger items. To avoid losing data when that is done, the entire content of the ledger segment is "dumped" to a history record and stored elsewhere, presumably on a larger but lower cost device with lower performance characteristics.

This text was extracted from a PDF file.
This is the abbreviated version, containing approximately 53% of the total text.

Page 1 of 2

Get Condition

The herein described record management algorithm permits dynamic creation and retrieval of historical records by conditional "get" and "put" means. It is not possible to continue to record data in a fixed space indefinitely, so provision is made to return to the starting point and record new transactions over the previously written ledger items. To avoid losing data when that is done, the entire content of the ledger segment is "dumped" to a history record and stored elsewhere, presumably on a larger but lower cost device with lower performance characteristics.

At the time of dumping, a linkage is established between the current record and the historical record. This linkage provides data needed on subsequent dumps to knit the newly formed history records with their predecessors, forming a contiguous historical record.

A new instruction referred to as a GET-Condition (Time), causes machine instructions to be compiled to "roll back" the record to its previous status "as of" an earlier point in time. Field values in the "data" portion of the record will be restored from the "ledger" portion, if they have been changed since the time specified. A record that has been rolled back cannot be updated in a typical application without causing erroneous application results, but it can be used for historical reports, comparisons, etc.

Conditions in this context will be of the same general form as usual - Field name, Op, value, but note that several new cases exist.

Where Time is desired (available from ledger signature data) a special form may be used. "Time equal to," "time greater than," and "time less than," are phrases strange and hard to use. Instead, the fo...