OPTIMIZATION OF QUERIES ON A REPOSITORY BASED ON CONSTRAINTS ON HOW THE DATA IS STORED IN THE REPOSITORY

• US 20120271814A1
• Filed: 04/24/2012
• Published: 10/25/2012
• Est. Priority Date: 07/08/2005
• Status: Active Grant

• Current Assignee: Muralidhar Krishnaprasad, Vikas Arora, Zhen Liu
• Original Assignee: Muralidhar Krishnaprasad, Vikas Arora, Zhen Liu
• Inventors: Krishnaprasad, Muralidhar, Liu, Zhen Hua, Arora, Vikas
• Granted Patent: US 8,793,267 B2
• Time in Patent Office: Days
• US Class Current: 707/713
• CPC Class Codes: G06F 16/14 Details of searching files based on file metadata
• CPC Class Codes: G06F 16/24547 Optimisations to support specific applications; Extensibility of optimisers

Abstract

Constraints that restrict how corresponding identifiable groups of files are stored in a database, are enforced on corresponding file data. In response to a query on any data from an identifiable group of files, the effect of the constraint on how the corresponding data is stored is determined. The original query is rewritten, based on the effect of the constraint, so that the rewritten query is directed to a particular subset of the data stored in the database. Consequently, the search space is restricted to an identifiable subset of the database and execution of the rewritten query is more efficient than execution of the original query.

Claims

1. A computer-implemented method comprising:

storing, within database objects managed by a database system, data files contained in a directory of folders, each folder of said directory of folders containing at least one data file of said data files;

in said database, storing metadata that, for each folder of said directory of folders, defines one or more constraints, wherein said one or more constraints includes a physical constraint that specifies that storage of any data file in said each folder is restricted to at least one specified database object of said database objects;

wherein for at least two of said directory of folders, a first folder includes a first data file that is restricted to a first database object and a second folder includes a second data file that is restricted to a second database object;

wherein the first database object is different than the second database object;

receiving, at the database system, a query that complies with a query language;

in response to receiving said query;

reading said metadata defining said one or more constraints;

based on (1) said query and (2) the one or more constraints defined by the read metadata, said database system making a determination of how data required by the query is stored in said database; and

based on the determination on how data required by the query is stored in said database, rewriting the query to generate a re-written query that specifies a restriction based on said at least one specified database object, wherein the received query did not specify said restriction.