Interview Q&A / PostgreSQL
PostgreSQL interview questions
Indexes, EXPLAIN, transactions and isolation, JSONB and the Postgres specifics backend interviews probe.
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- Is the hash index in PostgreSQL worth using compared to B-tree?
A hash index supports only equality lookups. Since PostgreSQL 10 it is crash-safe and can be slightly smaller than a B-tree for long keys, but B-tree also handles equality plus ranges and sorting, so B-tree stays the default.
IntermediateQuick answer1 min read