Wei Tang

US Patent:

20110161310, Jun 30, 2011

Filed:

Dec 30, 2009

Appl. No.:

12/649608

Inventors:

Wei Tang - Torrance CA, US
Dehui Zhang - Beijing, CN

International Classification:

G06F 17/30

US Classification:

707714, 707718, 707E17017

Abstract:

Apparatus, systems, and methods may operate to retrieve at least a portion of a first database query plan comprising a first tree and at least a portion of a second database query plan comprising a second tree. Further activities may include comparing relations and operations in the first tree and the second tree to identify differences. The differences may be found in the join order of the relations, and/or deleted, inserted, updated, or swapped ones of the operations based on operation signatures. Potential regression in query plan performance based on the differences may be indicated using a visual and/or audible alarm, and the differences may be published. Additional apparatus, systems, and methods are disclosed.

US Patent:

20160179889, Jun 23, 2016

Filed:

Dec 23, 2014

Appl. No.:

14/581797

Inventors:

- Dayton OH, US
Chuchu Wu - Los Angeles CA, US
Wei Tang - Torrance CA, US

Assignee:

Teradata US, Inc. - Dayton OH

International Classification:

G06F 17/30

Abstract:

Query conditions are received in a cache from a query optimizer of a Database Management System (DBMS). Dynamic statistics for the query conditions are maintained in the cache. Actual statistics are received in the cache after the query conditions are executed in the DBMS. Entropy-based estimated selectivity values for executing the query conditions are provided to the query optimizer to develop a query plan for executing queries having the query conditions. The entropy-based estimated selectivity values based, at least in part, on the dynamic statistics and the actual statistics.

US Patent:

20160179890, Jun 23, 2016

Filed:

Dec 23, 2014

Appl. No.:

14/581737

Inventors:

- DAYTON OH, US
Hien Trong To - Los Angeles CA, US
Wei Tang - Torrance CA, US

Assignee:

TERADATA US, INC. - DAYTON OH

International Classification:

G06F 17/30

Abstract:

Sets of joins against relations in a query are identified. An optimal order for processing the joins is determined. The optimal order is then processed by an enhanced genetic algorithm to generate a second optimal order for processing the joins. The second optimal order is at least as good as the optimal order. The second optimal order is used when developing a query plan for processing the query in a Database Management System (DBMS).