Explain about conflict serializability in DBMS

Conflict serializability orders any conflicting operations in the same way as some serial execution. A pair of operations is said to conflict if they operate on the same data item and one of them is a write operation.

That means

• Readi(x) readj(x) - non conflict   read-read operation

• Readi(x) writej(x) - conflict         read-write operation.

• Writei(x) readj(x) - conflic      t write-read operation.

• Writei(x) writej(x) - conflict      write-write operation.

Where I and j denote two different transactions Ti and Tj.

Precedence graph

It is used to check conflict serializability.

The steps to check conflict serializability are as follows −

• For each transaction T, put a node or vertex in the graph.

• For each conflicting pair, put an edge from Ti to T_j.

• If there is a cycle in the graph then schedule is not conflict serializable else schedule is conflict serializable.

Example 1

The cycle is present so it is not conflict serializable.

Example 2

The cycle is not present, so it is conflict serializable.

Example 3

The cycle is not present, so it is conflict serializable.

Bhanu Priya

Updated on 06-Jul-2021 14:50:27

• Related Questions & Answers
• Explain the precedence graph for testing conflict serializability(DBMS)
• Explain about nested queries in DBMS
• Explain about concurrent transactions in DBMS
• What is the term serializability in DBMS?
• Explain about 2NF with an example in DBMS
• Explain about triggers and active databases in DBMS
• Explain about two phase locking (2PL) protocol(DBMS)
• Explain about the Time stamp ordering protocol in DBMS
• Explain about insert command in Structured query language in DBMS
• Check the view serializability for the given schedules(DBMS)
• Explain about Create, Insert, Select command in structure query language (DBMS)?
• When do we say the schedule is conflict equivalent(DBMS)?
• Explain about financial strategy.
• Explain about Transfer pricing
• Explain about Varargs in java?