Skippy: a new snapshot indexing method for time travel in the storage manager

The storage manager of a general-purpose database system can retain consistent disk page level snapshots and run application programs "back-in-time" against long-lived past states, virtualized to look like the current state. This opens the possibility that functions, such as on-line trend analysis and audit, formerly available in specialized temporal databases, can become available to general applications in general-purpose databases. Up to now, in-place updating database systems had no satisfactory way to run programs on-line over long-lived, disk page level, copy-on-write snapshots, because there was no efficient indexing method for such snapshots. We describe Skippy, a new indexing approach that solves this problem. Using Skippy, database application code can run against an arbitrarily old snapshot, and iterate over snapshot ranges, as efficiently it can access recent snapshots, for all update workloads. Performance evaluation of Skippy, based on theoretical analysis and ...

• Type: Conference
• Year: 2008
• Where: SIGMOD
• Authors: Ross Shaull, Liuba Shrira, Hao Xu
• Keywords: Copy-on-write Snapshots, Database, Disk Page Level, Page Level Snapshots, SIGMOD 2008