Title
Sprinkling Selections over Join DAGs for Efficient Query Optimization
Abstract
In optimizing queries, solutions based on AND/OR DAG can generate all possible join orderings and select placements before searching for optimal query execution strategy. But as the number of joins and selection conditions increase, the space and time complexity to generate optimal query plan increases exponentially. In this paper, we use join graph for a relational database schema to either pre- compute all possible join orderings that can be executed and store it as a join DAG or, extract joins in the queries to incrementally build a history join DAG as and when the queries are executed. The select conditions in the queries are appropriately placed in the retrieved join DAG (or, history join DAG) to generate optimal query execution strategy. We experimentally evaluate our query optimization technique on TPC-D/H query sets to show their effectiveness over AND/OR DAG query optimization strategy. Finally, we illustrate how our technique can be used for efficient multiple query optimization and selection of materialized views in data warehousing environments.
Year
Venue
Keywords
2002
Clinical Orthopaedics and Related Research
time complexity,relational database,query optimization,data warehousing,materialized views
Field
DocType
Volume
Query optimization,Hash join,Data mining,Query language,Recursive join,Computer science,Sargable,Theoretical computer science,Sort-merge join,Materialized view,Database,Query plan
Journal
cs.DB/0202
Citations 
PageRank 
References 
0
0.34
8
Authors
3
Name
Order
Citations
PageRank
Satyanarayana R. Valluri11226.44
Soujanya Vadapalli2535.36
Kamalakar Karlapalem31269187.45