Let's understand the RAID first, RAID (Redundant Array of Independent Disks) is like having backup copies of your important files stored in different places on several hard drives or solid-state drives (SSDs). If one drive stops working, your data is still safe because you have other copies stored on the other drives. It’s like having a safety net to protect your files from being lost if one of your drives breaks down.
Now let's understand RAID with view of Database,
RAID in a Database Management System (DBMS) is a technology that combines multiple physical disk drives into a single logical unit for data storage. The main purpose of RAID is to improve data reliability, availability, and performance. Some Keys Points of RAID to understand:-
1.Reliability: How many disk faults can the system tolerate?
2.Availability: What fraction of the total session time is a system in uptime mode, i.e. how available is the system for actual use?
3.Performance: How good is the response time? How high is the throughput (rate of processing work)? Note that performance contains a lot of parameters, not just the two.
4.Capacity: Given a set of N disks each with B blocks, how much useful capacity is available to the user?
There are Different RAID Levels that are as follows:-
RAID-0 (Stripping)
RAID-1 (Mirroring)
RAID-2 (Bit-Level Stripping with Dedicated Parity)
RAID-3 (Byte-Level Stripping with Dedicated Parity)
RAID-4 (Block-Level Stripping with Dedicated Parity)
RAID-5 (Block-Level Stripping with Distributed Parity)
RAID-6 (Block-Level Stripping with two Parity Bits).
Some Advantages of RAID are:-
1.Data Redundancy
2.Scalability
3.Performance Enhancement.
Some Disadvantages of RAID are:-
1.Cost Factor is more
2.Complexity in terms of setup.
3.Decreased Performance in parity calculations in terms of RAID-5 and RAID-6.
