Query Restartability via State Token Mechanism

Solution Overview

Problem

Existing systems face challenges in efficiently handling query processing and data retrieval across distributed databases, particularly in scenarios where connections are lost due to network failures or data movement, leading to incomplete or duplicate results and increased latency.

Innovation Solution

The implementation of a restart token mechanism that allows systems to resume query processing without intermediate results, by generating a token that represents the operations performed to determine results, enabling the continuation of query processing from the last known result without reprocessing intermediate data.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of time

If the system streams multiple responses with partial results to the device, then the system can provide continuous data flow and reduce latency, but if a connection is lost the system must reprocess intermediate results causing duplicate data and increased latency

Engineering Contradiction:

Improvequery processing latencyVSAvoidconnection failure resilience

Core Design Contradiction:

Loss of timeVSReliability

Solution Approach 1:

The system performs preliminary action by capturing the state of query processing at the point of connection failure and packaging it into a restart token. This token contains sufficient information about which results have been sent and what the current processing state is, enabling the system to resume exactly where it left off without reprocessing intermediate results. The restart token is generated in advance as part of the normal query processing flow, before any connection failure occurs.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The system extracts the essential state information from the complex query processing operation and separates it into a standalone restart token. This token can be transmitted independently through the connection and contains only the critical information needed for resumption (which results were sent, current processing position). By extracting this state information into a separate, transmissible format, the system enables reliable recovery without needing to resend the entire query or reprocess intermediate results.

Inventive Principle:

Principle #2Taking out (Extraction)

2Productivity

If the system allows parallel processing of queries, then processing speed increases, but connection failures cause incomplete or duplicate results

Engineering Contradiction:

Improvequery processing throughputVSAvoidresult completeness and accuracy

Core Design Contradiction:

ProductivityVSManufacturing precision

Solution Approach 1:

The system implements feedback by continuously monitoring connection status and using the restart token to provide information about processing progress. When a connection failure occurs, the restart token serves as feedback about which results have been successfully transmitted and what the current processing state is. This feedback mechanism enables the system to adjust its behavior on recovery, ensuring it resumes from the correct position and avoids duplicate results while maintaining the benefits of parallel processing.

Inventive Principle:

Principle #23Feedback

3Reliability

If the system reprocesses intermediate results after connection failure, then it can ensure result consistency, but it causes duplicate data transmission and increases latency

Engineering Contradiction:

Improveresult consistencyVSAvoidretry processing time

Core Design Contradiction:

ReliabilityVSLoss of time

Solution Approach 1:

The system performs preliminary action by capturing the state of query processing at the point of connection failure and packaging it into a restart token. This token contains sufficient information about which results have been sent and what the current processing state is, enabling the system to resume exactly where it left off without reprocessing intermediate results. The restart token is generated in advance as part of the normal query processing flow, before any connection failure occurs.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The system extracts the essential state information from the complex query processing operation and separates it into a standalone restart token. This token can be transmitted independently through the connection and contains only the critical information needed for resumption (which results were sent, current processing position). By extracting this state information into a separate, transmissible format, the system enables reliable recovery without needing to resend the entire query or reprocess intermediate results.

Inventive Principle:

Principle #2Taking out (Extraction)

Data Source

PatentUS20240427770A1Query restartability

Publication Date: 2024.12.26 GOOGLE LLC

AI summary

Methods, systems, and apparatus, including computer programs encoded on computer storage media, for restarting a query using a token. One of the methods includes receiving, by a computer from a requesting device, a query; determining, using a data storage system, a current result responsive to the query; generating, using the current result, a restart token that represents operations performed to determine a plurality of results responsive to the query including the current result responsive to the query and that can be used to determine a new result responsive to the query that was not included in the plurality of results responsive to the query; and providing, to the requesting device, a message that includes a) first data for the restart token that represents operations performed to determine the plurality of results responsive to the query and b) second data for the current result responsive to the query.