System and method of query processing with schema change in JSON document store

• US 10,664,471 B2
• Filed: 12/29/2017
• Issued: 05/26/2020
• Est. Priority Date: 09/30/2015
• Status: Active Grant

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Cao, Zhao, Feng, Yuan, Li, Tao, Wang, Lanjun, Xu, Lin Hao
• Primary Examiner(s): Alam, Shahid A
• Application Number:
  US15/857,753
• Publication Number:
  US 20180121498A1
• Time in Patent Office: 879 Days
• Field of Search: 707731
• CPC Class Codes: G06F 16/211 Schema design and management
• CPC Class Codes: G06F 16/2423 Interactive query statement specification based on a database schema
• CPC Class Codes: G06F 16/245 Query processing
• CPC Class Codes: G06F 16/289 Object oriented databases
• CPC Class Codes: G06F 16/9535 Search customisation based on user profiles and personalisation

Abstract

An information processing system, a computer readable storage medium, and a method of managing a query to find a set of JSON documents in a multi-schema JSON document store. A query engine receives a first query to find at least one JSON document in a plurality of sets of JSON documents stored in the JSON document store, each set of JSON documents being organized in a unique JSON schema version related to a unique JSON schema version of each other set of JSON documents by at least one schema change. The first query is organized in a first unique JSON schema version. A query translator translates the first query into a plurality of queries based on the plurality of schema changes. The first and the plurality of queries are executed to provide a collective set of query results.

Claims

1. A computer-implemented method of managing a query to find a set of JavaScript Object Notation (JSON) documents in a JSON document store, the method comprising:

receiving a first query to find at least one JSON document in a plurality of sets of JSON documents stored in a JSON document store, each set of JSON documents in the plurality being organized in a unique JSON schema version related to a unique JSON schema version of each other set of JSON documents in the plurality of sets of JSON documents by at least one schema change, the first query being organized in a first unique JSON schema version from a plurality of unique JSON schema versions of the respective plurality of sets of JSON documents;

maintaining a schema change graph of a plurality of schema changes between respective pairs of the plurality of unique JSON schema versions;

translating the first query into a plurality of queries based on the plurality of schema changes, wherein each of the plurality of queries is organized in a respective unique JSON schema version from the plurality of unique JSON schema versions;

executing the first query, organized in the first unique JSON schema version, on a first set of JSON document in the plurality of sets of JSON documents to provide a first query result, where the first set of JSON documents is organized in the first unique JSON schema version;

executing each of the plurality of queries, each query organized in a respective unique JSON schema version, on a respective one of the plurality of sets of JSON documents to provide a respective one of a plurality of query results, where the each of the plurality of sets of JSON documents is organized in the respective each unique JSON schema version;

collecting the first query result and the plurality of query results into a collective set of query results; and

returning the collective set of query results.

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

formatting the collective set of query results in the first unique JSON schema version prior to returning the collective set of query results.

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

receiving a user-selection of the first JSON schema version with the first query.

4. The computer-implemented method of claim 1, wherein the plurality of unique JSON schema versions includes one or more of

an object of an unordered set of name/value pairs;

and

an array of an ordered collection of values; and

wherein each value is a string, a number, a true/false flag, an array or an object.

5. The computer-implemented method of claim 1, wherein the plurality of schema changes from the first unique JSON schema version to the respective each of the plurality of unique JSON schema versions comprises at least one of adding an element to the first unique JSON schema version and deleting a schema element from the first unique JSON schema version.

6. The computer-implemented method of claim 1, wherein the plurality of schema changes from the first unique JSON schema version to the plurality of unique JSON schema versions comprises renaming a schema element of the first unique JSON schema version.

7. The computer-implemented method of claim 1, wherein the at least one schema change from the first unique JSON schema version to a second unique JSON schema version in the plurality of unique JSON schema versions comprises changing a type of a schema element of the first unique JSON schema version.

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

accessing a schema tracker to retrieve a schema change graph of schema changes between pairs of the plurality of unique JSON schema versions for translating the first query into the plurality of queries based on the at least one schema change.

9. An information processing system that can manage a received query to find a set of JavaScript Object Notation (JSON) documents in a multi-schema JSON document store, the information processing system comprising:

a memory;

a JSON document store for storing a plurality of sets of JSON documents where each set of JSON documents in the plurality being organized in a unique JSON schema version related to a unique JSON schema version of each other set of JSON documents in the plurality by at least one schema change;

a query engine for executing queries against the plurality of sets of JSON documents;

a query translator for translating a first query into a plurality of queries based on the plurality of schema changes, the first query being organized in a first unique JSON schema version from a plurality of unique JSON schema versions of the respective plurality of sets of JSON documents;

a schema tracker for maintaining a schema change graph of a plurality of schema changes between respective pairs of the plurality of unique JSON schema versions; and

a processor, communicatively coupled with the memory, the JSON document store, the query engine, the query translator, and the schema tracker, the processor, responsive to computer instructions, performing a method to find a set of JSON documents in a JSON document store, the method comprising;

receiving the first query to find at least one JSON document in the plurality of sets of JSON documents stored in the JSON document store;

translating the first query into a plurality of queries based on the plurality of schema changes, wherein each of the plurality of queries is organized in a respective unique JSON schema version from the plurality of unique JSON schema versions;

executing the first query, organized in the first unique JSON schema version, on a first set of JSON document in the plurality of sets of JSON documents to provide a first query result, where the first set of JSON documents is organized in the first unique JSON schema version;

executing each of the plurality of queries, each query organized in a respective unique JSON schema version, on a respective one of the plurality of sets of JSON documents to provide a respective one of a plurality of query results, where the each of the plurality of sets of JSON documents is organized in the respective each unique JSON schema version;

collecting the first query result and the plurality of query results into a collective set of query results; and

returning the collective set of query results.

10. The information processing system of claim 9, where the processor, responsive to computer instructions, performing the method comprising:

formatting the collective set of query results in the first unique JSON schema version prior to returning the set of query results.

11. The information processing system of claim 9, where the processor, responsive to computer instructions, performing the method comprising:

receiving a user-selection of the first JSON schema version with the first query.

12. The information processing system of claim 9, wherein the plurality of unique JSON schema versions includes one or more of

an object of an unordered set of name/value pairs;

and

an array of an ordered collection of values; and

wherein each value is a string, a number, a true/false flag, an array or an object.

13. The information processing system of claim 9, wherein the plurality of schema changes from the first unique JSON schema version to the respective each of the plurality of unique JSON schema versions comprises at least one of

adding an element to the first unique JSON schema version;

deleting a schema element from the first unique JSON schema version;

renaming a schema element of the first unique JSON schema version; and

changing a type of a schema element of the first unique JSON schema version.

14. A non-transitory computer readable storage medium, comprising computer instructions which, responsive to being executed by a processor, cause the processor to perform operations to find a set of JavaScript Object Notation (JSON) documents in a JSON document store, the operations comprising:

receiving a first query to find at least one JSON document in a plurality of sets of JSON documents stored in a JSON document store, each set of JSON documents in the plurality being organized in a unique JSON schema version related to a unique JSON schema version of each other set of JSON documents in the plurality of sets of JSON documents by at least one schema change, the first query being organized in a first unique JSON schema version from a plurality of unique JSON schema versions of the respective plurality of sets of JSON documents;

maintaining a schema change graph of a plurality of schema changes between respective pairs of the plurality of unique JSON schema versions;

translating the first query into a plurality of queries based on the plurality of schema changes, wherein each of the plurality of queries is organized in a respective unique JSON schema version from the plurality of unique JSON schema versions;

executing the first query, organized in the first unique JSON schema version, on a first set of JSON document in the plurality of sets of JSON documents to provide a first query result, where the first set of JSON documents is organized in the first unique JSON schema version;

executing each of the plurality of queries, each query organized in a respective unique JSON schema version, on a respective one of the plurality of sets of JSON documents to provide a respective one of a plurality of query results, where the each of the plurality of sets of JSON documents is organized in the respective each unique JSON schema version;

collecting the first query result and the plurality of query results into a collective set of query results; and

returning the collective set of query results.

15. The computer readable storage medium of claim 14, wherein the processor performed operations further comprising:

formatting the collective set of query results in the first unique JSON schema version prior to returning the collective set of query results.

16. The computer readable storage medium of claim 14, wherein the processor performed operations further comprising:

receiving a user-selection of the first JSON schema version with the first query.

17. The computer readable storage medium of claim 14, wherein the plurality of unique JSON schema versions includes one or more of

an object of an unordered set of name/value pairs;

and

an array of an ordered collection of values; and

wherein each value is a string, a number, a true/false flag, an array or an object.

18. The computer readable storage medium of claim 14, wherein the plurality of schema changes from the first unique JSON schema version to the respective each of the plurality of unique JSON schema versions comprises at least one of adding an element to the first unique JSON schema version and deleting a schema element from the first unique JSON schema version.

19. The computer readable storage medium of claim 14, wherein the plurality of schema changes from the first unique JSON schema version to the plurality of unique JSON schema versions comprises renaming a schema element of the first unique JSON schema version.

20. The computer readable storage medium of claim 14, wherein the at least one schema change from the first unique JSON schema version to a second unique JSON schema version in the plurality of unique JSON schema versions comprises changing a type of a schema element of the first unique JSON schema version.