Unit06 dbms

[object Object],[object Object]

[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object]

Transaction Concept ,[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object]

Example of Fund Transfer ,[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object]

Example of Fund Transfer (Cont.) ,[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object]

Example of Fund Transfer (Cont.) ,[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object]

ACID Properties ,[object Object],[object Object],[object Object],[object Object],[object Object],A transaction is a unit of program execution that accesses and possibly updates various data items.To preserve the integrity of data the database system must ensure:

Transaction State ,[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object]

Implementation of Atomicity and Durability ,[object Object],[object Object],[object Object],[object Object],[object Object],[object Object]

Implementation of Atomicity and Durability (Cont.) ,[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object]

Concurrent Executions ,[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object]

Schedules ,[object Object],[object Object],[object Object],[object Object],[object Object],[object Object]

Schedule 1 ,[object Object],[object Object]

Schedule 3 ,[object Object],In Schedules 1, 2 and 3, the sum A + B is preserved.

Serializability ,[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object]

Conflicting Instructions ,[object Object],[object Object],[object Object],[object Object]

Conflict Serializability ,[object Object],[object Object]

Conflict Serializability (Cont.) ,[object Object],[object Object],Schedule 3 Schedule 6

Conflict Serializability (Cont.) ,[object Object],[object Object]

View Serializability ,[object Object],[object Object],[object Object],[object Object],[object Object]

View Serializability (Cont.) ,[object Object],[object Object],[object Object],[object Object],[object Object]

Other Notions of Serializability ,[object Object],[object Object]

Recoverable Schedules ,[object Object],[object Object],[object Object],Need to address the effect of transaction failures on concurrently running transactions.

Cascading Rollbacks ,[object Object],[object Object]

Cascadeless Schedules ,[object Object],[object Object],[object Object]

Concurrency Control ,[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object]

Concurrency Control vs. Serializability Tests ,[object Object],[object Object],[object Object],[object Object],[object Object],[object Object]

Weak Levels of Consistency ,[object Object],[object Object],[object Object],[object Object],[object Object]

Levels of Consistency in SQL-92 ,[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object]

Transaction Definition in SQL ,[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object]

Implementation of Isolation ,[object Object],[object Object],[object Object],[object Object]

Testing for Serializability ,[object Object],[object Object],[object Object],[object Object],[object Object],x y

Example Schedule (Schedule A) + Precedence Graph ,[object Object],[object Object],T 5 T 3 T 4 T 1 T 2

Test for Conflict Serializability ,[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object]

Test for View Serializability ,[object Object],[object Object],[object Object],[object Object],[object Object]

Lock-Based Protocols ,[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object]

Lock-Based Protocols (Cont.) ,[object Object],[object Object],[object Object],[object Object],[object Object]

Lock-Based Protocols (Cont.) ,[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object]

Pitfalls of Lock-Based Protocols ,[object Object],[object Object],[object Object],[object Object]

Pitfalls of Lock-Based Protocols (Cont.) ,[object Object],[object Object],[object Object],[object Object],[object Object]

The Two-Phase Locking Protocol ,[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object]

The Two-Phase Locking Protocol (Cont.) ,[object Object],[object Object],[object Object]

Lock Conversions ,[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object]

Automatic Acquisition of Locks ,[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object]

Automatic Acquisition of Locks (Cont.) ,[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object]

Implementation of Locking ,[object Object],[object Object],[object Object],[object Object],[object Object]

Lock Table ,[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],Granted Waiting

Graph-Based Protocols ,[object Object],[object Object],[object Object],[object Object],[object Object]

Tree Protocol ,[object Object],[object Object],[object Object],[object Object]

Timestamp-Based Protocols ,[object Object],[object Object],[object Object],[object Object],[object Object]

Timestamp-Based Protocols (Cont.) ,[object Object],[object Object],[object Object],[object Object],[object Object]

Timestamp-Based Protocols (Cont.) ,[object Object],[object Object],[object Object],[object Object],[object Object],[object Object]

Example Use of the Protocol ,[object Object],[object Object],T 1 T 2 T 3 T 4 T 5 read( Y ) read( X ) read( Y ) write( Y ) write( Z ) read( Z ) read( X ) abort read( X ) write( Z ) abort write( Y ) write( Z )

Correctness of Timestamp-Ordering Protocol ,[object Object],[object Object],[object Object],[object Object],transaction with smaller timestamp transaction with larger timestamp

Thomas’ Write Rule ,[object Object],[object Object],[object Object],[object Object],[object Object],[object Object]

Validation-Based Protocol ,[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object]

Validation-Based Protocol (Cont.) ,[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object]

Validation Test for Transaction T j ,[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object]

Schedule Produced by Validation ,[object Object],T 14 T 15 read ( B ) read ( B ) B : = B-50 read ( A ) A : = A+50 read ( A ) ( validate ) display ( A + B ) ( validate ) write ( B ) write ( A )

Multiple Granularity ,[object Object],[object Object],[object Object],[object Object],[object Object],[object Object]

Example of Granularity Hierarchy ,[object Object],[object Object],[object Object],[object Object],[object Object]

Intention Lock Modes ,[object Object],[object Object],[object Object],[object Object],[object Object]

Compatibility Matrix with Intention Lock Modes ,[object Object],IS IX S S IX X IS IX S S IX X                         

Multiple Granularity Locking Scheme ,[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object]

Unit06 dbms

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Unit06 dbms