QUERY PROCESSING WITH BOUNDED STALENESS FOR TRANSACTIONAL MUTATIONS IN NoSQL DATABASE

Patent metadata

Field	Value
Publication number	US-2018150503-A1
Application number	US-201615363313-A
Country	US
Kind code	A1
Filing date	Nov 29, 2016
Priority date	Nov 29, 2016
Publication date	May 31, 2018
Grant date	—

Abstract

A computer-implemented method executed on one or more processors is provided for processing a query for a NoSQL (non-structured query language) database. The computer-implemented method includes periodically monitoring active transactions that started and are committing dirty versions before a specific time, sending a query to fetch a state of the active transactions, and receiving a query result. The computer-implemented method further includes, if the query result includes active transactions, performing a normal query that scans dirty and committed versions. The computer-implemented method further includes, if the query result includes no active transactions, due to a time window indicating a specified staleness, sending a simplified query that scans only committed versions.

First claim

1 . A computer-implemented method executed on one or more processors for processing a query for a NoSQL (non-structured query language) database, the method comprising:
periodically monitoring active transactions that started and are committing dirty versions before a specific time; sending a query to fetch a state of the active transactions; receiving a query result; if the query result includes active transactions, performing a normal query that scans dirty and committed versions; and if the query result includes no active transactions, due to a time window indicating a specified staleness, sending a simplified query that scans only committed versions.

2 . The method of claim 1 , wherein the normal query includes retrieving all dirty versions of a transaction state from the NoSQL database.

3 . The method of claim 2 , wherein the normal query further includes moving the dirty versions to committed.

4 . The method of claim 3 , wherein the normal query further includes altering the transaction state from committed to finished.

5 . The method of claim 1 , wherein the single query is sent for a committed version.

6 . The method of claim 1 , wherein, when active transactions are detected, the NoSQL database guarantees that the query result reflects all the latest committed versions at the indicated time window.

7 . The method of claim 1 , wherein the specified staleness is bounded.

8 . The method of claim 1 , wherein the active transactions are monitored before a predetermined time period.

9 . A computer system for processing a query for a NoSQL database, the computer system comprising:
a memory; and at least one processor in communication with the memory, wherein the computer system is configured to:
periodically monitor active transactions that started and are committing dirty versions before a specific time;
send a query to fetch a state of the active transactions;
receive a query result;
if the query result includes active transactions, perform a normal query that scans dirty and committed versions; and
if the query result includes no active transactions, due to a time window indicating a specified staleness, send a simplified query that scans only committed versions.

10 . The computer system of claim 9 , wherein the normal query includes retrieving all dirty versions of a transaction state from the NoSQL database.

11 . The computer system of claim 10 , wherein the normal query further includes moving the dirty versions to committed.

12 . The computer system of claim 11 , wherein the normal query further includes altering the transaction state from committed to finished.

13 . The computer system of claim 9 , wherein the single query is sent for a committed version.

14 . The computer system of claim 9 , wherein, when active transactions are detected, the NoSQL database guarantees that the query result reflects all the latest committed versions at the indicated time window.

15 . The computer system of claim 9 , wherein the specified staleness is bounded.

16 . The computer system of claim 9 , wherein the active transactions are monitored before a predetermined time period.

17 . A non-transitory computer readable storage medium comprising a computer readable program for processing a query for a NoSQL database, wherein the computer readable program when executed on a computer causes the computer to perform the steps of:
periodically monitoring active transactions that started and are committing dirty versions before a specific time; sending a query to fetch a state of the active transactions; receiving a query result; if the query result includes active transactions, performing a normal query that scans dirty and committed versions; and if the query result includes no active transactions, due to a time window indicating a specified staleness, sending a simplified query that scans only committed versions.

18 . The non-transitory computer readable storage medium of claim 17 , wherein the normal query includes retrieving all dirty versions of a transaction state from the NoSQL database.

19 . The non-transitory computer readable storage medium of claim 18 , wherein the normal query further includes moving the dirty versions to committed.

20 . The non-transitory computer readable storage medium of claim 19 , wherein the normal query further includes altering the transaction state from committed to finished.

Assignees

• IBM

Inventors

• Horii Hiroshi H

Classifications

• G06F11/3065

  Monitoring arrangements determined by the means or processing involved in reporting the monitored data (error or fault reporting or logging G06F11/0766) · CPC title

• G06F2201/87

  Monitoring of transactions · CPC title

• G06F16/2453

  Query optimisation · CPC title

• G06F16/2379 Primary

  Updates performed during online database operations; commit processing · CPC title

• G06F2201/835

  Timestamp · CPC title