Serial Schedule
|
Non-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.
|
A non-serial schedule is a schedule where the operations of a group of concurrent transactions are interleaved.
|
Transactions are performed in serial order.
|
Transactions are performed in non-serial order, but result should be same as serial.
|
No interference between transactions
|
Concurrency problem can arise here.
|
It
does not matter which transaction is executed first, as long as every
transaction is executed in its entirely from the beginning to end.
|
The problem we have seen earlier lost update, uncommitted data, inconsistent analysis is arise if scheduling is not proper.
|
A serial schedule gives the benefits of concurrent execution without any problem
|
In this schedule there is no any benefit of concurrent execution.
|
Serial schedule that does interleaved the actions of different transactions.
|
Where non-serial schedule has no only fix actions of any transaction.
|
EXAMPLE:
If some transaction T is long, the other transaction must wait for T to complete all its operations.
|
EXAMPLE:
In this schedule the execution of other transaction goes on without waiting the completion of T.
|
If we consider transaction to be independent serial schedule is correct based on (property ACID) above assumption is valid.
|
The
objective behind serializability is to find the non-serial schedule
that allows transactions to execute concurrently without interfering
one another.
|
- Blogger Comment
- Facebook Comment
Subscribe to:
Post Comments
(
Atom
)
0 comments:
Post a Comment