What SQL topics should I prepare for a DevOps interview?

For the optimization side, learn how to read an execution plan and understand why a query uses a table scan instead of an index seek. Review indexes, common join types, CTEs, window functions, and SARGability. In particular, know how applying functions or implicit conversions to a column in a WHERE clause can prevent the database from using an index efficiently.

A good quick-study checklist would include SELECT queries, filtering, aggregation, GROUP BY and HAVING, INNER and OUTER JOINs, subqueries, CTEs, transactions, normalization, indexes, execution plans, and query parameterization. Practice explaining not only whether a query returns the right result, but also how it behaves as the data grows.

The SQL requirement may indicate that the position combines DevOps responsibilities with database work, so clarify the expected scope if you can. A DevOps engineer does not necessarily need to be a database specialist, but being able to troubleshoot queries, understand schema and indexing basics, and discuss performance tradeoffs is very useful.

Focus on hands-on preparation instead of memorizing a list of interview questions. Build a small database with several related tables, practice writing joins and stored procedures, and review normalization. You should be comfortable explaining how you would design tables, retrieve data, and improve a slow query. A small project will help you understand the concepts much faster than studying isolated questions.