Principles of Distributed Database Systems

Transcription

1 M. Tamer Özsu Patrick Valduriez Principles of Distributed Database Systems Third Edition <f)spri ringer

2 Contents 1 Introduction Distributed Data Processing What is a Distributed Database System? Data Delivery Alternatives Promises of DDBSs Transparent Management of Distributed and Replicated Data Reliability Through Distributed Transactions Improved Performance Easier System Expansion Complications Introduced by Distribution Design Issues Distributed Database Design Distributed Directory Management Distributed Query Processing Distributed Concurrency Control Distributed Deadlock Management Reliability of Distributed DBMS Replication Relationship among Problems Additional Issues Distributed DBMS Architecture ANSI/SPARC Architecture A Generic Centralized DBMS Architecture Architectural Models for Distributed DBMSs Autonomy Distribution Heterogeneity Architectural Alternatives Client/Server Systems Peer-to-Peer Systems Multidatabase System Architecture 35 xi

3 xii Contents 1.8 Bibliographic Notes 38 2 Background Overview of Relational DBMS Relational Database Concepts Normalization Relational Data Languages Review of Computer Networks Types of Networks Communication Schemes Data Communication Concepts Communication Protocols Bibliographic Notes 70 3 Distributed Database Design Top-Down Design Process Distribution Design Issues Reasons for Fragmentation Fragmentation Alternatives Degree of Fragmentation Correctness Rules of Fragmentation Allocation Alternatives Information Requirements Fragmentation Horizontal Fragmentation Vertical Fragmentation Hybrid Fragmentation Allocation Allocation Problem Information Requirements Allocation Model Solution Methods Data Directory Conclusion Bibliographic Notes Database Integration Bottom-Up Design Methodology Schema Matching Schema Heterogeneity Linguistic Matching Approaches Constraint-based Matching Approaches Learning-based Matching Combined Matching Approaches Schema Integration 147

4 Contents xiii 4.4 Schema Mapping Mapping Creation Mapping Maintenance Data Cleaning Conclusion Bibliographic Notes Data and Access Control View Management Views in Centralized DBMSs Views in Distributed DBMSs Maintenance of Materialized Views Data Security Discretionary Access Control Multilevel Access Control Distributed Access Control Semantic Integrity Control Centralized Semantic Integrity Control Distributed Semantic Integrity Control Conclusion Bibliographic Notes Overview of Query Processing Query Processing Problem Objectives of Query Processing Complexity of Relational Algebra Operations Characterization of Query Processors Languages Types of Optimization Optimization Timing Statistics Decision Sites Exploitation of the Network Topology Exploitation of Replicated Fragments Use of Semijoins Layers of Query Processing Query Decomposition Data Localization Global Query Optimization Distributed Query Execution Conclusion Bibliographic Notes 220

5 Contents Query Decomposition and Data Localization Query Decomposition Normalization Analysis Elimination of Redundancy Rewriting Localization of Distributed Data Reduction for Primary Horizontal Fragmentation Reduction for Vertical Fragmentation Reduction for Derived Fragmentation Reduction for Hybrid Fragmentation Conclusion Bibliographic NOTES 241 Optimization of Distributed Queries Query Optimization Search Space Search Strategy Distributed Cost Model Centralized Query Optimization Dynamic Query Optimization Static Query Optimization Hybrid Query Optimization Join Ordering in Distributed Queries Join Ordering Semijoin Based Algorithms Join versus Semijoin Distributed Query Optimization Dynamic Approach Static Approach Semijoin-based Approach Hybrid Approach Conclusion Bibliographic Notes 292 Multidatabase Query Processing Issues in Multidatabase Query Processing Multidatabase Query Processing Architecture Query Rewriting Using Views Datalog Terminology Rewriting in GAV Rewriting in LAV Query Optimization and Execution Heterogeneous Cost Modeling Heterogeneous Query Optimization 314

6 Contents xv Adaptive Query Processing Query Translation and Execution Conclusion Bibliographie Notes Introduction to Transaction Management Definition of a Transaction Termination Conditions of Transactions Characterization of Transactions Formalization of the Transaction Concept Properties of Transactions Atomicity Consistency Isolation Durability Types of Transactions Flat Transactions Nested Transactions Workflows Architecture Revisited Conclusion Bibliographic Notes Distributed Concurrency Control Serializability Theory Taxonomy of Concurrency Control Mechanisms Locking-Based Concurrency Control Algorithms Centralized 2PL Distributed 2PL Timestamp-Based Concurrency Control Algorithms Basic TO Algorithm Conservative TO Algorithm Multiversion TO Algorithm Optimistic Concurrency Control Algorithms Deadlock Management Deadlock Prevention Deadlock Avoidance Deadlock Detection and Resolution "Relaxed" Concurrency Control Non-Serializable Histories Nested Distributed Transactions Conclusion Bibliographic Notes 401

7 xvi Contents 12 Distributed DBMS Reliability Reliability Concepts and Measures System, State, and Failure Reliability and Availability Mean Time between Failures/Mean Time to Repair Failures in Distributed DBMS Transaction Failures Site (System) Failures Media Failures Communication Failures Local Reliability Protocols Architectural Considerations Recovery Information Execution of LRM Commands Checkpointing Handling Media Failures Distributed Reliability Protocols Components of Distributed Reliability Protocols Two-Phase Commit Protocol Variations of 2PC Dealing with Site Failures Termination and Recovery Protocols for 2PC Three-Phase Commit Protocol Network Partitioning Centralized Protocols Voting-based Protocols Architectural Considerations Conclusion Bibliographic Notes Data Replication Consistency of Replicated Databases Mutual Consistency Mutual Consistency versus Transaction Consistency Update Management Strategies Eager Update Propagation Lazy Update Propagation Centralized Techniques Distributed Techniques Replication Protocols Eager Centralized Protocols Eager Distributed Protocols Lazy Centralized Protocols Lazy Distributed Protocols Group Communication 482

8 xvii 13.5 Replication and Failures Failures and Lazy Replication Failures and Eager Replication Replication Mediator Service Conclusion Bibliographic Notes 493 Parallel Database Systems Parallel Database System Architectures Objectives Functional Architecture Parallel DBMS Architectures Parallel Data Placement Parallel Query Processing Query Parallelism Parallel Algorithms for Data Processing Parallel Query Optimization Load Balancing Parallel Execution Problems Intra-Operator Load Balancing Inter-Operator Load Balancing Intra-Query Load Balancing Database Clusters Database Cluster Architecture Replication Load Balancing Query Processing Fault-tolerance Conclusion Bibliographic Notes 547 Distributed Object Database Management Fundamental Object Concepts and Object Models Object Types and Classes Composition (Aggregation) Subclassing and Inheritance Object Distribution Design Horizontal Class Partitioning Vertical Class Partitioning Path Partitioning Class Partitioning Algorithms Allocation Replication Architectural Issues 566

9 xvüi Contents Alternative Client/Server Architectures Cache Consistency Object Management Object Identifier Management Pointer Swizzling Object Migration Distributed Object Storage Object Query Processing Object Query Processor Architectures Query Processing Issues Query Execution Transaction Management Correctness Criteria Transaction Models and Object Structures Transactions Management in Object DBMSs Transactions as Objects Conclusion Bibliographic Notes Реег-to-Peer Data Management Infrastructure Unstructured P2P Networks Structured P2P Networks Super-peer P2P Networks Comparison of P2P Networks Schema Mapping in P2P Systems Pairwise Schema Mapping Mapping based on Machine Learning Techniques Common Agreement Mapping Schema Mapping using IR Techniques Querying Over P2P Systems Top-k Queries Join Queries Range Queries Replica Consistency Basic Support in DHTs Data Currency in DHTs Replica Reconciliation Conclusion Bibliographic Notes Web Data Management Web Graph Management Compressing Web Graphs Storing Web Graphs as S-Nodes 661

10 Contents xix 17.2 Web Search Web Crawling Indexing Ranking and Link Analysis Evaluation of Keyword Search Web Querying Semistructured Data Approach Web Query Language Approach Question Answering Searching and Querying the Hidden Web Distributed XML Processing Overview of XML XML Query Processing Techniques Fragmenting XML Data Optimizing Distributed XML Processing Conclusion Bibliographic Notes Current Issues: Streaming Data and Cloud Computing Data Stream Management Stream Data Models Stream Query Languages Streaming Operators and their Implementation Query Processing DSMS Query Optimization Load Shedding and Approximation Multi-Query Optimization Stream Mining Cloud Data Management Taxonomy of Clouds Grid Computing Cloud architectures Data management in the cloud Conclusion Bibliographic Notes 762 References 765 Index 833