Loading
Topic
Index keys, included columns, covering indexes, selectivity, sort order, and index maintenance trade-offs.
Practice items tagged with SQL Indexing.
Designs a narrow covering index from predicates and ordering, then weighs eliminated lookups against storage, write overhead, cache efficiency, overlap, and maintenance cost.
Writes predicates the optimizer can use as index search arguments, then proves the effect through plans and reads while balancing computed columns, composite indexes, and write overhead.
Converts local-day boundaries to UTC once, preserving correct daylight-saving behavior and index use on stored UTC timestamps.