Briefly describe concurrency execution, Database Management System

Assignment Help:

Briefly describe concurrency execution?

Lock - based protocols

Locks

There are several modes in which a data item may be locked in this section we restrict our attention to two modes

Ø Shared

Ø Exclusive

T1 : lock - x(B );

read(B);

B:=B-50;

write(B);

unlock(B);

Lock-x(A);

read(A);

A:=A+50;

write(A);

unlock(A).

Related Discussions:- Briefly describe concurrency execution

Explain what is ddl, Explain what is DDL? DDL - Data Definition Languag...

Explain what is DDL? DDL - Data Definition Language: statements used to define the database structure or schema. Some examples: CREATE - to create objects in the database ALT

What are the disadvantages of relational data, What are the disadvantages o...

What are the disadvantages of relational data ? Disadvantages • Performance - If the number of tables among that relationships to be established are large and the tables t

Define aggregate functions, Define Aggregate functions and what aggregate f...

Define Aggregate functions and what aggregate functions supported by the MySQL To calculate a summary value from a set of individual values and uses one of the functions known

Data base administrator, What is the role of a database administrator?

What is the role of a database administrator?

Explain the static or conservative two phase locking, Explain the Static or...

Explain the Static or conservative Two Phase Locking: Static (or conservative) Two Phase Locking: In this type of scheme, all the data items are locked earlier than any opera

Select statement-data manipulation language, SELECT Statement This stat...

SELECT Statement This statement is used for retrieving information from the databases. It can be coupled with many clauses. Let us talk about these clauses in more detail:

Database administrator, Database Administrator One of the main perpos...

Database Administrator One of the main perpose for having the database management system is to have control of both data or programs accessing that data. The person having li

Explain the function of input controls, Explain the function of input contr...

Explain the function of input controls. Identify four types of input control and explain the function of each. Provide an example of a data integrity error that could occur i

What is null described testing for null in sql?, What is NULL? Give an exa...

What is NULL? Give an example to described testing for NULL in SQL? The NULL SQL keyword is used to represent either a missing value or a value which is not applicable in a re

Explain data independence, Explain data independence ? Data independenc...

Explain data independence ? Data independence is the capacity to modify the schema at one stage of a database system without having to change the schema at the further level.

Write Your Message!

Name

Email id

Message

Verfication Code

User Account

All Pages