Method of optimizing a query having an existi subquery and a not-exists subquery
Number of patents in Portfolio can not be more than 2000
United States of America Patent
Stats
-
Mar 4, 2003
Grant Date -
N/A
app pub date -
Feb 17, 2000
filing date -
Feb 17, 2000
priority date (Note) -
Expired
status (Latency Note)
Importance
Abstract
An optimization technique for SQL queries, a program storage device storing the optimization program, and an apparatus for optimizing a query is provided. A query is analyzed to determine whether it includes the WHERE clause which contains an 'EXISTS' subquery and a 'NOT EXISTS' subquery, or EXISTS-equivalent subqueries, in Boolean factor. If so, the subsumption test is performed on two subqueries. Then, the compensation predicate is applied to one of them, to perform the QGM transformation of the query. One subquery block is stacked on top of the other subquery block, in order to eliminate one subquery. This procedure allows the transformed query to perform more efficiently than the original query while providing same results. The query is then executed in the computer to efficiently retrieve data from the relational database.
First Claim
Family
International Classification(s)
Cited Art Landscape
Patent Citation Ranking
Advertisement
Advertisement
Advertisement
Recipient Email Address
Recipient Email Address
Comment
Recipient Email Address
Add to Portfolio(s)
To add this patent to one, or more, of your portfolios, simply click the add button.
This Patent is in these Portfolios:
Add to additional portfolios:
Last Refreshed On:
Changes done successfully