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数据库系统学习笔记

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CMU 课程 《数据库系统概念》

  • Database system

    • storage manager
    • query processor component
    • transaction management component

  • Indexing

    • Ordered Indices
    • B Tree Indices
      • Queries
      • Updates
        • Insertion
        • Deletion
    • Hash Indices
      • Linear Probe Hashing
      • Robin Hood Hashing
      • Cuckoo Hashing
      • Chained Hashing
      • Extendible Hashing
        • Extendible Hash Table
      • Linear Hashing
    • Bitmap Indices

  • Query Processing

    • Selection
    • Sorting
      • External Sort-Merge Algorithm
    • Aggregations
    • Join
      • Nested-Loop Join
      • Block Nested-Loop Join
      • Indexed Nested-Loop Join
      • Merge Join
      • Hash Join
    • Modifications
      • Inserts
      • Updates
      • Deletes

  • Query Optimization

  • Concurrency Control

    • Lock-Based Protocols

      • 2PL/S2PL/R2PL
        • grow phase
        • shrink phase
      • Multiple-granularity Locking Protocol
        • IS/IX/S/SIX/X locks

    • Deadlock Handling

      • prevention
      • detection
      • recovery

    • Timestamp-Based Protocols

      • Ordering the transaction requests

    • Validation-Based Protocols

    • Multiversion Schemes

      • Combining with other protocols

    • Snapshot isolation

  • Transaction Concurrency Problems

    • Dirty Read
      • Read a uncorrect data.
    • Unrepeated Read
      • A transaction get two different value between two read operations.
    • Phantom Read
      • A transaction insert between B transaction’s two times of read operation, then B transaction get two different amount of ouputs.

  • Transaction isolation levels (high->low)

    • Serializable
    • Repeatable Read
    • Read Committed
    • Read Uncommitted

  • Isolation implementation

    • Locking
      • likes 2PL.
    • Timestamps
      • Ensure data items access order by timestamp (or serial number). Each data item holds two timestamps, read timestamp and write timestamp, and each transaction get a timestamp when it start.
    • Multi-version and snapshots
      • No lock, no waiting, good performance, widely adopted.

  • Advanced topics on Transaction

    • Concurrenency control ofern become bottlenecks in main-memory database.
    • Online Index Creation
    • B Tree index-concurrency control
      • crabbing protocols
      • B-link trees
    • Concurrency Control in Main-Memory Databases
      • lock-free data structure

  • Recovery System

    • Log Records
    • Checkpointing
    • ARIES
      • log sequence numbers
        • pageLSN
        • flushedLSN
        • …
      • recovery
        • Analysis pass
        • Redo pass
        • Unfo pass

  • Server System Architectures

    • Transaction-Server Architecture
      • Server processes
      • Lock manager process
      • Database writer process
      • Log writer process
      • Checkpoint process
      • Process monitor process
      • Buffer pool
      • Lock table
      • Log buffer
      • Query plan cache
    • Data servers

  • Distributed Databases

    • Partitioning Schemes
    • Distributed Concurrency Control
      • Centralized coordinator
      • Middleware
      • Decentralized coordinator
    • Partitioning
      • Naive Table Partitioning
      • Horizontal Table Partitioning