Why query speed matters for app responsiveness Even a perfectly engineered UI can feel sluggish when a database call blocks the main thread

Why query speed matters for app responsiveness Even a perfectly engineered UI can feel sluggish when a database call blocks the main thread or adds noticeable latency. In production, the time spent waiting for the database often dominates the end‑to‑end response time, especially on mobile networks where every millisecond counts. Keeping queries fast is therefore a hidden driver of perceived performance. Indexing basics and common pitfalls Indexes are the primary tool for reducing the amount of data the engine must scan. A well‑chosen index should cover the exact columns used in WHERE, JOIN, and ORDER BY clauses. When an index...