Using multiversion data for non-interfering execution of write-only transactions
Divyakant Agrawal, Venkatram Krishnaswamy · 1991
A modular version control mechanism is developed for executing write-only transactions with minimal interference to read-write transactions using multiversion data.The execution of write-only transactions is completely independent of the underlying concurrency control protocol.The version control mechanism provides the versatility of using any conflict-baaed concurrency control protocol for read-write transaction synchronization.An integrated version control mechanism is presented in which both read-only and write-only transactions are handled symmetrically, and are independent of the concurrency control mechanism.In addition, there is negligible version control related overhead for executing read-only and write-only transactions.Our approach of non-interfering execution of write-onlY transactions is particularly useful in database systems consisting of abstract data objects where blind-write operations are dominant.1 rameter to the history.Similarly, in an airlines reservation system, which stores operation histories, reservation and cancellation transaction can be executed as blind decrement and increment transactions, respectively.Thus, in such systems it seems natural that transactions should be classified into three categories: read-only, read-write, and write-only] transactions.After classifying the transactions into these categories, the question arises if multiversion 1we we ~~~g the term writ G-on /y instead of blid-w-it e for the sake of uniformity.a write lock on y.If the lock is not available, T is delayed.Otherwise, T creates a version of y, which gets a version number equal to tn(T), when T commits.