hard20 pts · first answer countsindexingpostgresqlperformance

Index for the few pending rows

A jobs table has 50 million rows, 99.9% with status 'done'. Workers run: SELECT * FROM jobs WHERE status = 'pending' ORDER BY created_at LIMIT 100. Which index is best?

A.CREATE INDEX ON jobs (status)B.CREATE INDEX ON jobs USING hash (status)C.No index, because status has very few distinct values and the planner will always choose a sequential scanD.CREATE INDEX ON jobs (created_at) WHERE status = 'pending'

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