The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Oct. 30, 2007
Filed:
Mar. 13, 2003
Joseph Serge Limoges, Etobicoke, CA;
Robert A. Begg, Scarborough, CA;
Dominique J. Evans, Toronto, CA;
William T. O'connell, Etobicoke, CA;
Klaus Bernhard Schiefer, Pickering, CA;
Timothy J. Vincent, Toronto, CA;
Joseph Serge Limoges, Etobicoke, CA;
Robert A. Begg, Scarborough, CA;
Dominique J. Evans, Toronto, CA;
William T. O'Connell, Etobicoke, CA;
Klaus Bernhard Schiefer, Pickering, CA;
Timothy J. Vincent, Toronto, CA;
International Business Machines Coporation, Armonk, NY (US);
Abstract
A method, computer program product and computing device for promoting reuse of previously generated access plans are disclosed. SQL statements containing literals are amended so as to substitute a parameter marker for each literal. Amended statements are provided to the DBMS along with parameters including the substituted literals and a substitution indicator indicating that the substitution has been performed. The DBMS assesses the soundness of the substitutions that are performed. Soundness may be measured in terms of the semantic correctness of the amended statement and the likelihood that the literal substitution will improve DBMS efficiency. If a substitution is unsound, the DBMS may obtain and optimize the original version of the amended SQL statement. Otherwise, the amended statement is optimized. Advantageously, SQL statements originally differing only in the value of one or more literals may become functionally equivalent, and the reuse of cached, previously generated access plans is thus promoted.