Paper Info
Title
Scalable architecture and query optimization fortransaction-time DBs with evolving schemas
Abstract
The problem of archiving and querying the history of a database is made more complex by the fact that, along with the database content, the database schema also evolves with time. Indeed, archival quality can only be guaranteed by storing past database contents using the schema versions under which they were originally created. This causes major usability and scalability problems in preservation, retrieval and querying of databases with intense evolution histories, i.e., hundreds of schema versions. This scenario is common in web information systems and scientific databases that frequently accumulate that many versions in just a few years. Our system, Archival Information Management System (AIMS), solves this usability issue by letting users write queries against a chosen schema version and then performing for the users the rewriting and execution of queries on all appropriate schema versions. AIMS achieves scalability by using (i) an advanced storage strategy based on relational technology and attribute-level-timestamping of the history of the database content, (ii) suitable temporal indexing and clustering techniques, and (iii) novel temporal query optimizations. In particular, with AIMS we introduce a novel technique called CoalNesT that achieves unprecedented performance when temporal coalescing tuples fragmented by schema changes. Extensive experiments show that the performance and scalability thus achieved greatly exceeds those obtained by previous approaches. The AIMS technology is easily deployed by plugging into existing DBMS replication technologies, leading to very low overhead; moreover, by decoupling logical and physical layers provides multiple query interfaces, from the basic archive&query features considered in the upcoming SQL standards, to the much richer temporal XML/XQuery capabilities proposed by researchers.
Year
DOI
Venue
2010
10.1145/1807167.1807192
SIGMOD Conference
Keywords
Field
DocType
scalable architecture,suitable temporal indexing,appropriate schema version,richer temporal xml,schema version,novel temporal query optimizations,query optimization fortransaction-time dbs,database schema,aims technology,past database content,schema change,database content,relational algebra,physical layer,query optimization,sql,relational databases,performance,information management system
Query optimization,Data mining,Star schema,Schema migration,Computer science,Semi-structured model,View,Database schema,Temporal database,Information schema,Database
Conference
Citations 
PageRank 
References 
6
0.57
38
Authors
3
Name
Order
Citations
PageRank
Hyun Jin Moon131114.28
Carlo Curino2201290.35
Carlo Zaniolo343051447.58