US 7,461,052 B2Granted

Abstract query plan

AssigneeInternational Business Machines Corporation

InventorsRichard D. Dettinger, Daniel P. Kolz

Life of this patent

Estimating the term…

Loading patent…

Abstract

A method and apparatus, and article of manufacture are provided to process an abstract query of a database abstraction constructed over an underlying physical data storage mechanism. The database may comprise a single data source, or a federated source spanning multiple systems. Embodiments of the invention process an abstract query by generating an intermediate representation of the abstract query. In one embodiment, the intermediate representation comprises an abstract query plan. An abstract query plan includes a combination of elements from the data abstraction model and elements relating to the underlying physical data storage mechanism. Once generated, a back-end component may easily traverse the abstract query plan to generate an SQL statement (or other resolved query) corresponding to the abstract query. Further, once constructed, the abstract query plan provides a platform for many different optimizations that may be selected by a user or by the runtime component inspecting the abstract query plan prior to creating the resolved query.

Claims10

Dependent claims

A method of processing an abstract query, comprising:

receiving, from a requesting entity, an abstract query composed from a plurality of logical fields, wherein each logical field specifies (i) a name used to identify the logical field, (ii) an access method that maps the logical field to a data source in a database;
identifying (i) a set of data sources referenced by the plurality of logical fields in the abstract query and (ii) a set of relationships between the set of data sources;
determining an acyclic graph representation of the set of data sources;
generating an abstract query plan, wherein the abstract query plan comprises:
(a) a plurality of table instances, wherein each table instance includes:
(i) an indication of a data source associated with that table instance;
(ii) each of the logical fields included in the abstract query that depend on data present in the indicated data source;
and
(iii) conditions used to limit data selected from the indicated data source;
and
(b) a set of join relationships that indicates how the plurality of table instances are related to one another;
performing at least one optimization of the abstract query plan to generate an optimized abstract query plan;
and
traversing the optimized abstract query plan to generate a resolved query of the set of data sources.

11 more elements

Dependencies are inferred from the claim text.

Facts

Application: 11/005,418Filed 6 Dec 2004
Published: US 2006/0122993 A18 Jun 2006
Granted: 2 Dec 2008
Term ends: Not estimatedThe source records don’t support an estimate.

Classification10 codes

G06F 16/24526
Query translation: internal representations for queries
G06F 16/24549
Query rewriting; Transformation: run-time optimisation
G06F 16/2471
Special types of queries, e.g. statistical queries, fuzzy queries or distributed queries: distributed queries
Y10S 707/99932
Database or file accessing: access augmentation or optimizing