Question

What is data retrieval? Which aspect of data retrieval affect the system performance?​

Answer 1

Data retrieval means obtaining data from a database management system such as ODBMS. ... In this case, it is considered that data is represented in a structured way, and there is no ambiguity in data. In order to retrieve the desired data the user present a set of criteria by a query.

mark ❤️

Answer 2

Answer:

Data Retrieval in Disk Operation in OS.

Explanation:

Author of the question didn't mentioned where he is seeking data retrieval. Assuming its more of OS related question i am answering this. Might not be the best answer, little bit rusty on this.

So Data Retrieval here is more prominent to load data from secondary memory to primary memory so that the executing program can use it. eg

you want to use a stored word document say your bio data in D: drive, and want to edit it. MS Word will load that bit of information in primary memory before you can start using it. But at the same time it might be possible other programs like media player, your browser want to access some local files. All these local files are stored at different addresses and your read/write head has to go to and fro to constantly fetch the request. The OS manages all these retrieval request with smart algorithms. Before going to algos, we need to understand what are the crucial parameters which can affect the performance.

Seek Time:Seek time is the time taken to locate the disk arm to a specified track where the data is to be read or write. So the disk scheduling algorithm that gives minimum average seek time is better.

Rotational Latency: Rotational Latency is the time taken by the desired sector of disk to rotate into a position so that it can access the read/write heads. So the disk scheduling algorithm that gives minimum rotational latency is better.

Transfer Time: Transfer time is the time to transfer the data. It depends on the rotating speed of the disk and number of bytes to be transferred.

Disk Access Time:

[google more on this and the algos used like STFS,FCFS, refer geek for geeks]

Some of the techniques which also play a crucial role in minimizing the request and enhancing performance.

- Caching

- Virtual Memory

Again all these are big topics in themself. frame your answer as per the required marks.