Storage and Retrieval

Question 1

Fundamentally, what does a database do

Answer 1

When we give it data, we expect it to store the data and when we ask for it, we expect to get the data we stored back

Question 2

What is a log

Answer 2

In the general sense, a log is an append-only sequence of records. It can either be binary or human readable

Question 3

What is one way of efficiently finding data stored in the database

Answer 3

Making use of indexes.

Question 4

What are indexes

Answer 4

An index is a kind of data structure that holds additional metadata about the primary data stored. It basically acts as a landmark/signpost that helps to quickly identify or locate data.

Question 5

Effect of Indexes on database performance

Answer 5

Adding or removing indexes only have effect on the performance of queries. Often times, when indexes are added, there’s extra overhead on writes because the indexes also have to be updated. However, if chosen appropriately, read performance is usually increased with indexes.