New algorithms for join and grouping operations

• Published in: Computer science (Berlin, Germany) Vol. 27; no. 1; pp. 3 - 27
• Main Author: Graefe, Goetz
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer-Verlag 01.02.2012
• Subjects: Computer Hardware; Computer Science; Computer Systems Organization and Communication Networks; Data Structures and Information Theory; Software Engineering/Programming and Operating Systems; Special Issue Paper; Theory of Computation; Intersection; Outer join; Buffer pool; Duplicate removal; Merging; Relational databases; Mistake; Difference; Union; Equivalence classes; Robust performance; Order-preserving; Map-reduce; Query optimization choice; Query execution algorithms; Uniqueness; Error; Grouping; Sort order; SQL; Semi-join; Query processing; Interesting orderings; Inner join; Run generation; Group by

Traditional database query processing relies on three types of algorithms for join and for grouping operations. For joins, index nested loops join exploits an index on its inner input, merge join exploits sorted inputs, and hash join exploits differences in the sizes of the join inputs. For grouping...