This dissertation offers 1. a formal model for streaming workflows tailored for transformation and 2. transformation rules for streaming workflows described based on that formal model. The validity of the transformation rules is shown by formally proofing equivalence. The validity of the formal model is exhibited by the fact that valid transformation rules could be defined. Transformation of streaming workflows is the 1st step towards automatic optimization of streaming workflows. By offering a formal model and transformation rules, this dissertation reveals that it is feasible to build a self-optimizing Streaming Workflow System…..
Contents
Introduction
Monitoring a River
Sensor Data Problems and Challenges
Streaming Workłow System
Optimization
Objectives
Research Questions
Ļesis Structure
Formal Model
Monitoring a River with a Streaming Workłow
Behavior of Activities
Assumptions on the System Runtime Design Choices
Position in the System
Equivalence
Monitoring a River the Same Way, but Different Equivalence of Activities
Equivalence of Views
Equivalence of Streaming Workłows
Local and Global Equivalence
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Transformation Rules
Zip Rule
Copycat Rule
Shared Loop Rule
Copy Elimination/Bypass Rule
A Multi-Step Example
Monitoring a River Slightly Differently
Tuple-based Transformation Rules
Union Associativity Rule
Selection Pushdown Rule
Masquerade Rule
Other Rules
Advanced Transformation Rules
Aggregate Split Rule
Shared Join Rule
Related Work
Complications
Query Graph Transformations
Adaptive Processing
Optimization Criteria
Provenance
Approximation
Conclusions
Monitoring a River: Overview…..
Source: University of Twente