ON-THE-FLY READING OF ENTIRE DATABASES

A common database need is to obtain a global-read, which Is a consiste nt read of an entire database. To avoid terminating normal system acti vity, and thus improve availability, we propose an on the-fly algorith m that reads database entities incrementally and allows normal transac tions to proceed concurrently. The algorithm assigns each entity a col or based on whether the entity has been globally read, and a shade bas ed on how normal transactions have accessed the entity. Serializabilit y of execution histories is ensured by requiring normal transactions t o pass both a color test and a shade test before being allowed to comm it. Our algorithm improves on a color only-based scheme from the liter ature; the color-only scheme does not guarantee serializability.