Explain Composite and Covering Indexes in MySQL
Company: ByteDance
Role: Software Engineer
Category: Software Engineering Fundamentals
Difficulty: medium
Interview Round: Technical Screen
Overview: Explain how a MySQL composite B-tree index on tenant, status, and creation time serves different query shapes. Cover the leftmost-prefix rule, equality and range predicates, ordering, clustered-key lookups, and when a covering index avoids extra table reads.
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