DBMS & SQL chapters
  1. 01Database Concepts & Relational Architecture
  2. 02Comprehensive SQL Engine & Joins
  3. 03Functional Dependencies & Normalization
  4. 04Transactions & Concurrency Control
  5. 05Indexing, B+ Trees & NoSQL Systems

Chapter 4 · Database Systems

Transactions & Concurrency Control

6 topics in 2 parts

Full lessonPython Programming · Control Flow

Key ideas

External View 1 (Web User Portal) External View 2 (Finance & Billing) External View 3 (Analytics & BI) ↕ LOGICAL DATA INDEPENDENCE ↕ CONCEPTUAL / LOGICAL SCHEMA LEVEL Entities, Relational Tables, Attributes, Constraints, Foreign Keys & Business Rules ↕ PHYSICAL DATA INDEPENDENCE ↕ INTERNAL / PHYSICAL STORAGE LEVEL B+ Tree Indexes, Hashing, Page Blocks, Compression, Record Offsets & RAID Storage
Transactions & Concurrency Control
Evaluation ParameterStandard Relational PatternProduction Optimization Impact
Storage Engine LayerDisk page blocks & buffer pool cacheMinimizes random disk I/O via sequential prefetching
Index UtilizationB+ Tree logarithmic search $O(\log N)$Avoids full table scans across millions of rows
Concurrency & LocksRow-level shared (S) and exclusive (X) locksPrevents race conditions while maximizing read throughput
Failure RecoveryWrite-Ahead Logging (WAL) / Undo-RedoGuarantees durability and instant crash recovery

All 6 topics in Transactions & Concurrency Control

  1. Transactions

    • ACID Properties of Transactions
    • Transaction States

  2. Concurrency

    • Recoverable & Cascadeless Schedules
    • Conflict Serializability
    • Two-Phase Locking (2PL)
    • Deadlock Schemes in DBMS