Commutativity and its Role in the Processing of Linear Recursion

We investigatetherole of commutativityin queryprocessing of linear recursion. We give a sufficientconditionfor two linear,function-free,constant-free,andrange-restricted rules to commute. The conditiondependson the form of the rules themselves.For a restrictedclassof rules, we showthattheconditionis necessaryandsufficientandcan betestedin polynomialtimein thesizeof therules. Using thealgebraicstructureof suchrules,we studytherelationshipof commutativitywith severalotherpropertiesof linear recursiverules. We show that commutativityis in the centerof severalimportantspecialclassesof linearrecursion,i.e.,separablerecursionandrecursionwith recursively redundantpredicates.

• Type: Conference
• Year: 1989
• Where: VLDB
• Authors: Yannis E. Ioannidis
• Keywords: Commutativitywith Severalotherpropertiesof Linear, Database, Linear, Linear Recursion, VLDB 1989