Locking Protocol: Method to Ensure Concurrency in a File Access Processor
Original Publication Date: 1989-Oct-01
Included in the Prior Art Database: 2005-Jan-29
The basic purpose of a file access processor is to manage a set of objects (files within directories) for a set of users. These objects may be shared, requiring a high degree of concurrency for a file access processor. Because the environment allows sharing, a mechanism must be established that will ensure concurrency during sharing. This concurrency is based on a compatibility scheme devised for System R and Structured Query Language/Data System (SQL/DS) with the following extension: For each file define a logical object identifier. Hold locks on catalog (relational) rows only while obtaining the lock on the logical object and during commit.