Frequently asked questions for MySQL 8.0 Database Developer (1Z0-909): prerequisites, difficulty, what to focus on, and study strategy.
Yes — but not only “syntax”. It’s about correctness: NULL semantics, join behavior, grouping, and query plan reasoning with indexes.
Joins + aggregation + indexing/EXPLAIN. If you can predict outputs and spot non-sargable predicates, you’ll pick up many points.
No. Focus on the common families: string/date functions, aggregation, and the patterns used with JSON extraction and filtering.
Edge cases: NULLs in NOT IN, filtering after a LEFT JOIN, and accidentally changing the grouping granularity.