The Runtime Theory

topic / indexes-and-b-trees

Indexes and B-Trees

Use ordered page structures to narrow database searches.

Explore B-tree page organization, composite indexes, selectivity, index-only access, write amplification, and when a sequential scan is preferable.

1 article · 1 video · 1 trace · 1 request flow · 1 interview · 5 total

Articles

indexes and b treesSep 25, 2026

How a B-Tree Index Narrows a Database Search

A database index is an auxiliary structure that helps find rows without scanning every table page.

Request Flows

request flow · 5 stagesHow How a B-Tree Index Narrows a Database Search worksAn interactive concept flow for how a b-tree index narrows a database search, from its assumptions through the main operation and boundary checks.

Videos

indexes and b treesSep 25, 2026

Video lesson: How a B-Tree Index Narrows a Database Search

Recording brief and narration plan for a visual lesson on how a b-tree index narrows a database search.

Traces

trace 01 · systemTrace: How a B-Tree Index Narrows a Database SearchFollow the key state changes and boundary checks involved in how a b-tree index narrows a database search.

Interviews

medium · t2Explain How a B-Tree Index Narrows a Database SearchExplain the model, execution steps, complexity, and limits of how a b-tree index narrows a database search.

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