Explain different types of failures in DDBMS.
1. Soft Failure
Soft failure is the type of failure that causes the loss in volatile memory of the computer and not in the persistent storage. Here, the information stored in the non-persistent storage like main memory, buffers, caches or registers, is lost. They are also known as system crash. The various types of soft failures are as follows −
- Operating system failure.
- Main memory crash.
- Transaction failure or abortion.
- System generated error like integer overflow or divide-by-zero error.
- Failure of supporting software.
- Power failure.
2. Hard Failure
A hard failure is the type of failure that causes loss of data in the persistent or non-volatile storage like disk. Disk failure may cause corruption of data in some disk blocks or failure of the total disk. The causes of a hard failure are −
- Power failure.
- Faults in media.
- Read-write malfunction.
- Corruption of information on the disk.
- Read/write head crash of disk.
Recovery from disk failures can be short, if there is a new, formatted, and ready-to-use disk on reserve. Otherwise, duration includes the time it takes to get a purchase order, buy the disk, and prepare it.
3. Network Failure
Network failures are prevalent in distributed or network databases. These comprises of the errors induced in the database system due to the distributed nature of the data and transferring data over the network. The causes of network failure are as follows −
- Communication link failure.
- Network congestion.
- Information corruption during transfer.
- Site failures.
- Network partitioning.
Follow Us