SUPPORTING A JOIN OPERATION AGAINST MULTIPLE NOSQL DATABASES

• US 20190310978A1
• Filed: 06/25/2019
• Published: 10/10/2019
• Est. Priority Date: 03/30/2018
• Status: Active Grant

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Jiang, Peng Hui, Wang, Chun Hui, Zhou, Zan, Liu, Xin Peng, Li, Shuo, Wang, Xin Zhe
• Granted Patent: US 10,915,532 B2
• Time in Patent Office: Days
• CPC Class Codes: G06F 16/211 Schema design and management
• CPC Class Codes: G06F 16/2228 Indexing structures
• CPC Class Codes: G06F 16/2246 Trees, e.g. B+trees
• CPC Class Codes: G06F 16/2272 Management thereof
• CPC Class Codes: G06F 16/242 Query formulation
• CPC Class Codes: G06F 16/24544 Join order optimisation
• CPC Class Codes: G06F 16/2456 Join operations
• CPC Class Codes: G06F 16/28 Databases characterised by their database models, e.g. relational or object models
• CPC Class Codes: G06F 16/80 of semi-structured data, e.g. markup language structured data such as SGML, XML or HTML content-based retrieval of web data G06F16/95
• CPC Class Codes: G06F 16/93 Document management systems
• CPC Class Codes: G06F 16/95 Retrieval from the web

Abstract

Provided are techniques for supporting a join operation against multiple NoSQL databases. A search request with a field and a value for the field is received, wherein the search request is to be issued against a plurality of database divisions formed from NoSQL databases. A simple database search is performed against a structured index to generate a first result set. An extended database search is performed against a linear database division index to generate a second result set by: identifying a relationship for the field that identifies related fields and identifying documents for the field and the related fields using a linear database division index. The first result set and the second result set are merged to form a merged result set of documents. The documents from the merged result set are displayed in response to the search request.

Claims

1. A computer-implemented method, comprising:

receiving, using a processor of a computer, a search request with a field and a value for the field, wherein the search request is to be issued against a plurality of database divisions formed from NoSQL databases;

performing a simple database search against a structured index to generate a first result set;

performing an extended database search against a linear database division index to generate a second result set by;

identifying a relationship for the field, wherein the field is in a database division of the plurality of database divisions, and wherein the relationship identifies related fields in other database divisions; and

identifying documents using a linear database division index to search for the value in the related fields, wherein the linear database division index has a database division index for each of the plurality of database divisions, and wherein each database division index has entries for a value and an associated document;

merging the first result set and the second result set to form a merged result set of documents; and

displaying the documents from the merged result set in response to the search request.

2. The computer-implemented method of claim 1, further comprising:

dividing the NoSQL databases into the database divisions based on fields of the NoSQL databases; and

discovering a schema that describes which different fields of documents in different database divisions are related.

3. The computer-implemented method of claim 2, further comprising:

identifying relationships between the different fields.

4. The computer-implemented method of claim 1, further comprising:

receiving a request to build the linear database division index;

identifying a schema and the database divisions; and

building the linear database division index using the schema and the database divisions.

5. The computer-implemented method of claim 1, wherein the search request is executed at a server computer coupled to the NoSQL databases.

6. The computer-implemented method of claim 1, wherein the relationship is updated in response to any of:

a new field being added to a NoSQL database from the NoSQL databases, a new document being added to the NoSQL database, a document being deleted from the NoSQL database, a field being deleted from the NoSQL database, and a name of a field being changed in the NoSQL database.

7. The computer-implemented method of claim 1, wherein a Software as a Service (SaaS) is configured to perform method operations.

8-20. -20. (canceled)