#Indexing

What is indexing in databases? Explain how it improves query performance and what happens internally to achieve this efficiency.

Explain database concepts, specifically focusing on indexing and cardinality. Why are they important?

Describe what composite indexing is in databases. Provide examples of how and when it should be used effectively.

Explain strategies for database optimization, including indexing, sharding, and the effects of over-indexing on performance.

Discuss the differences between maps and sets (ordered/unordered) and how indexing works in databases.