Nga Ann Tran

US Patent:

8086598, Dec 27, 2011

Filed:

Feb 6, 2009

Appl. No.:

12/367415

Inventors:

Andrew Lamb - Arlington MA, US
Mitch Cherniack - Chelsea MA, US
Shilpa Lawande - Littleton MA, US
Nga Tran - Framingham MA, US

Assignee:

Hewlett-Packard Development Company, L.P. - Houston TX

International Classification:

G06F 17/30

US Classification:

707714, 707606, 707797

Abstract:

Methods, program products and systems for determining, for a database query that does not represent a snowflake schema, a graph comprising vertices each representing a table joined in the query, a directed edge between each pair of vertices of which a first vertex represents a first table and a second vertex represents a second table that is joined in the query with the first table, each of the edges representing one of an outer join and an inner join. Further determining, for the graph, a directed spanning tree that represents an ordering of joins in the query and includes all outer join edges in the graph.

US Patent:

8214352, Jul 3, 2012

Filed:

Nov 24, 2009

Appl. No.:

12/625482

Inventors:

Andrew Lamb - Arlington MA, US
Lakshmikant Shrinivas - Billerica MA, US
Shilpa Lawande - Littleton MA, US
Mitch Cherniack - Chelsea MA, US
Nga Tran - Framingham MA, US

Assignee:

Hewlett-Packard Development Company - Houston TX

International Classification:

G06F 17/30

US Classification:

707713, 707714, 707718

Abstract:

Methods, systems, and apparatus, including computer programs encoded on a computer storage medium, for modular query optimizer. In one aspect, a method includes selecting one or more projections from a set of projections for each table in a database query wherein each of the selected projections for the table has leads to an estimated lower execution cost for the query as compared to non-selected projections; generating join orders for the query based on data distribution of one or more of the selected projections among sites in a computer network wherein the join orders reflect different combinations of data distribution operations applied to the output of one or more of the query's joins; and selecting a join order from the join orders based on evaluation of the join orders using a cost model.

US Patent:

8312027, Nov 13, 2012

Filed:

Jun 5, 2012

Appl. No.:

13/489094

Inventors:

Andrew Lamb - Arlington MA, US
Lakshmikant Shrinivas - Billerica MA, US
Shilpa Lawande - Littleton MA, US
Mitch Cherniack - Chelsea MA, US
Nga Tran - Framingham MA, US

Assignee:

Hewlett-Packard Development Company, L.P. - Houston TX

International Classification:

G06F 17/30

US Classification:

707752, 707753, 707713, 707714, 707718

Abstract:

Computer programs encoded on a computer storage medium provide for a modular query optimizer. In one aspect, a computer program product includes selecting one or more projections from a set of projections for each table in a database query wherein each of the selected projections for the table has leads to an estimated lower execution cost for the query as compared to non-selected projections; generating join orders for the query based on data distribution of one or more of the selected projections among sites in a computer network wherein the join orders reflect different combinations of data distribution operations applied to the output of one or more of the query's joins; and selecting a join order from the join orders based on evaluation of the join orders using a cost model.