What is the 80 20 rule in SQL?

Excuse me, could you please elaborate on the concept of the 80 20 rule as it applies to SQL? I'm curious to understand how this principle, often associated with economics and business management, is relevant and utilized within the context of Structured Query Language. Is it a strategy for optimizing query performance? Or perhaps it relates to managing database storage and resource allocation? I'd appreciate any insights you can offer to clarify this concept in relation to SQL.