Teradata is made up of following components –
Processor Chip – The processor is the BRAIN of the Teradata system. It is responsible for all the processing done by the system. All task are done according to the direction of the processor.
Memory – The memory is known as the HAND of the Teradata system. Data is retrieved from the hard drives into memory, where processor manipulates, change or alter the data. Once changes are made in memory, the processor directs the information back to the hard drive for storage.
Hard Drives – This is known as the SPINE of the Teradata system. All the data of the Teradata system is stored in the hard drives. Size of hard drives reflects the size of the Teradata system.
Teradata has Linear Scalability
One of the most important asset of Teradata is that it has Linear Scalability. There is no limit on Teradata system. We can grow it to as many times as we want. Any time you want to double the speed of Teradata system, just double the numbers of AMPs and PE. This can be better explained with the help of an example –
Teradata takes every table in the system and spread evenly among different AMPs. Each Amp works on the portion of records which it holds.
Suppose a EMPLOYEE table has 8 different employee id’s. Now in a 2 AMP system each AMP will hold 4 rows in its DISK to accommodate total 8 rows.
2 AMP SYSTEM
At the time of data retrieval each AMP will work on its DISK and send 4 rows to PE for further processing. If we suppose, one AMP will take 1 microseconds (MS) to retrieve 1 rows, then the time taken to retrieve 4 rows is 4 MS. And as we know that AMPs work in parallel, so both the AMPs will retrieve all 8 records in 4 MS only (4 MS time for each AMP).
Now we double the AMP in our system, and we use total 4 AMP. As Teradata distribute the records evenly among all AMPs, so now each AMP will store 2 records of the table.
4 AMP SYSTEM
Now according to our time scale, the time taken by each AMP for retrieving 2 records is 2MS.
So all 4 AMPs, working parallel, will retrieve the 8 records in 2MS only. Which was previously 4MS for the 2 AMP system.
Hence we double our speed by doubling the number of AMPs in our system.
This is the power of parallelism in Teradata. It is also known as ‘DIVIDE and CONQUER’ theory, according to which we are dividing the work equally and getting the result faster. To achieve the desirable speed we can increase the number of AMPs accordingly.
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