What is Replication and Replication Schemes ?
What is Replication ?
Data replication is the process of storing data in more than
one site or node.
Data replication is the process in which the data is copied
at multiple location to improve the availability of data
Replication Schemes
The three replication schemes are as follows
- Full Replication
- No Replication
- Partial Replication
Full Replication
In full replication scheme, the database is available
to almost every location or user in communication network.
Advantages of full replication
- High availability of data, as database is available to almost every location.
- Faster execution of queries.
Disadvantages of full replication
- Concurrency control is difficult to achieve in full replication.
- Update operation is slower.
No Replication
No replication means, each fragment is stored exactly at one
location.
Advantages of no replication
- Concurrency can be minimized.
- Easy recovery of data.
Disadvantages of no replication
- Poor availability of data.
- Slows down the query execution process, as multiple clients are accessing the same server.
Partial Replication
Partial replication means only some fragments are replicated
from the database.
Advantages of Partial replication
- To provide a consistent copy of data across all the database nodes.
- To increase the availability of data.
- The reliability of data is increased through data replication.
- Data Replication supports multiple users and gives high performance.
Disadvantages of Partial replication
- More storage space is needed as storing the replicas of same data at different sites consumes more space.
- Data Replication becomes expensive when the replicas at all different sites need to be updated.
- Maintaining Data consistency at all different sites involves complex measures.
Post a Comment