Get Started. It's Free
or sign up with your email address
Rocket clouds
DBMS by Mind Map: DBMS

1. Transaction

1.1. Recovery

1.1.1. Log based Recovery Deferred modification technique Immediate modification technique

1.2. ACID property

1.2.1. Atomicity

1.2.2. Consistency

1.2.3. Isolation

1.2.4. Durability

2. Concurrency Control

2.1. Serializability

2.1.1. Serializable Schedule Conflict Serializable IF No Conflict Serializable View Serializable

2.1.2. Non-Serializable

2.2. Concurrency Control Techniques

2.2.1. Lock Based Protocol 2-phase locking Protocol 2 Phase Strict 2-phase locking Protocol Requirements Strict 2-phase locking Protocol Property Advantages Lock starting of transactions with same variable / Conservative 2-PL Lock Upgradation / Downgradation Upgradation Downgradation Advantages

2.2.2. Tree Protocol Advantages ensure Conflict Serializable Deadlock Free Unlock anyTime More Concurrency than 2-Phase Locking Disadvantages Cascading Rollback Can't be Cyclic

2.2.3. Time-Stamp Protocol 2-Data item R-timestamp(X) W-timestamp(X) Issues Ti issue Read(X) Ti issue Write(X) If wounded-wait -> No Starvation -> No Deadlock Advantages ensure Serializable Free from Deadlock DiaAdvantage Starvation THOMAS Write Rule Ignore outdated writes Its View Serializable with Blind Write . BCZ Blind write Won't Be Conflict Serial

2.2.4. Multiple Granularity 4 Level Database Region File Record Intention Mode Lock S [Shared] X [Exclusive] IS [Intension Shared] IX [Intension Exclusive] SIX [Shared & Intension Exclusive] Advantages Enhance Concurrency

2.3. Summary

2.3.1. Cascade Rollback & Cascade Abort is same

2.3.2. Dirty Read may be cause of Cascading abort

2.3.3. Schedule that avoid Cascading abort are Recoverable

2.3.4. All Schedule ⊃ Recoverable ⊃ Cascadeless Recoverable ⊃ Strict

3. File Organization