1. DBMS

Database Management System Highlevel

Manage data, allows applications to store, update and analyze the data and avoids Code, Data Overlap, Inconsistencies

• Layer 1: Query Processor (Operators, Cost Estimation, Query Optimization)
  • Parser - Check syntax and convert to Optimizer readable command, and check semantic
  • Optimizer - 优化器会生成许多能够满足查询请求的访问计划, 并选择具有最小成本的方案作为最终的访问计划 (Acess Plan), 通过 Estimator, Plan Generator
  • Rewriter - Convert to higher performance command
  • Executor - Execute
• Layer 2: Storage Manager (Storage Media)
  • Data Access - Handles access to the data stored in various storage media.
  • Buffer Manager - temporarily store data during processing.
  • Indexes, Filed, Data Layout - Organizes data and indexes in storage for efficient retrieval.
• Layer 3: Transaction Processing
  • Concurrency Control - Manages concurrent access to the database to ensure consistency.
  • Crash Recovery - Restores the system to a consistent state in the event of a crash.
  • Transaction Manager - Ensures that all database transactions are processed correctly and ensures ACID properties.
  • Recovery Manager
• Layer 4: Data
  • Schema Design - Designs the database schema and ensures efficient organization of data.
  • Detecting Redundancy - Identifies and eliminates redundancy in the database schema.
  • Schema Normalization - Normalizes the database schema to avoid anomalies.
  • Distributed Process (NoSQL and NewSQL) - Handles data distribution across multiple nodes, especially in distributed and NoSQL databases
  • Graph Data, Data Streams, Spatial Data - Manages specialized data types like graph data, streaming data, and spatial data.