Transcription of Chapter 13. Concurrency Control
{{id}} {{{paragraph}}}
Chapter 13. Concurrency ControlTable of contents Objectives Introduction Context Concurrent access to data Concept of transaction Transaction states and additional operations Interleaved Concurrency Interleaved vs simultaneous Concurrency Genuine vs appearance of Concurrency Read and write operations Need for Concurrency Control The lost update problem Uncommitted dependency (or dirty read / temporary update) Inconsistent analysis Other problems Need for recovery Transaction problems Desirable properties of transactions (ACID) Atomicity Consistency Isolation Durability or permanency Serialisability Schedules of transactions Serial schedules Non-serial schedules Serialisable schedule Locking techniques for Concurrency Control Types of locks Binary locks Shared and exclusive locks Use of the locking scheme Guarant
kind. This is discussed under serialisation below. Read and write operations We deal with transactions at the level of data items and disk blocks for the purpose of discussing concurrency control and recovery techniques. At this level, the database access operations that a transaction can include are: 7
Domain:
Source:
Link to this page:
Please notify us if you found a problem with this document:
{{id}} {{{paragraph}}}