METHOD AND SYSTEM FOR IMPROVING SQL DATABASE QUERY PERFORMANCE

摘要

Methods and systems for rewriting database queries, and in particular databases using Structured Query Language (SQL). The method comprises the steps of reviewing a SQL query statement having a SELECT list to determine if a view definition of the query has one or more unreferenced view columns; and removing at least one of the one or more unreferenced view columns from the view definition. The step of removing at least one of the one or more unreferenced view columns may also include removing all of the one or more unreferenced view columns from the view definition. This method improves performance of a query given that the spool file generated by the query rule contains minimal amount of data necessary for the query to be processed.