Question

What does the 80/20 rule mean, and how should it be applied to database application performance tuning?

Answer 1

Ans- 80/20 rule, (also known as Pareto principle, law of the vital few) states that out of many events about 80% of the effects come from 20% of the causes. It enables you to focus your minimal efforts in the area which makes the biggest difference.

It is axiom of business management which can be understood as 80% of the sales come from 20% of clients

In computer science it can be applied to optimization efforts. Lowell Arthur said that 20% of code has 80% error . Also 80% of software can be written in 20% of the given time. Conversely hardest 20% of code takes 80% of the time.

To apply on Database application-

1-summarise the original estimate data

2-use over(Partition by) to insert a running total and a partition tota

3-tidy up the table to remove future divide by zero errors.

4- add cumulative proportion columns

5- using SQL lead and lag functions to identify at least 80% of data by value .