# What are serial and non-serial schedule?

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What are serial and non-serial schedule?
posted Aug 24, 2014

Serial Schedule:

A serial schedule is a sequence of operation by a set of concurrent transaction that preserves the order of operations in each of the individual transactions.
Transactions are performed in serial order.
No interference between transactions
It does not matter which transaction is executed first, as long as every transaction is executed in its entirely from the beginning to end.
A serial schedule gives the benefits of concurrent execution without any problem
Serial schedule that does interleaved the actions of different transactions.
EXAMPLE:If some transaction T is long, the other transaction must wait for T to complete all its operations.
If we consider transaction to be independent serial schedule is correct based on (property ACID) above assumption is valid.
Serial Schedule
A serial schedule is a sequence of operation by a set of concurrent transaction that preserves the order of operations in each of the individual transactions.
Transactions are performed in serial order.
No interference between transactions
It does not matter which transaction is executed first, as long as every transaction is executed in its entirely from the beginning to end.
A serial schedule gives the benefits of concurrent execution without any problem
Serial schedule that does interleaved the actions of different transactions.
EXAMPLE:If some transaction T is long, the other transaction must wait for T to complete all its operations.
If we consider transaction to be independent serial schedule is correct based on (property ACID) above assumption is valid.

Non-Serial Schedule
A non-serial schedule is a schedule where the operations of a group of concurrent transactions are interleaved.
Transactions are performed in non-serial order, but result should be same as serial.
Concurrency problem can arise here.
The problem we have seen earlier lost update, uncommitted data, inconsistent analysis is arise if scheduling is not proper.
In this schedule there is no any benefit of concurrent execution.
Where non-serial schedule has no only fix actions of any transaction.
EXAMPLE:In this schedule the execution of other transaction goes on without waiting the completion of T.

Non-Serial Schedule
A non-serial schedule is a schedule where the operations of a group of concurrent transactions are interleaved.
Transactions are performed in non-serial order, but result should be same as serial.
Concurrency problem can arise here.
The problem we have seen earlier lost update, uncommitted data, inconsistent analysis is arise if scheduling is not proper.
In this schedule there is no any benefit of concurrent execution.
Where non-serial schedule has no only fix actions of any transaction.
EXAMPLE:In this schedule the execution of other transaction goes on without waiting the completion of T.