Seems like an obvious optimization to use a hash instead of scanning the array w... | Hacker News

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		consoomer on Aug 31, 2023 \| parent \| context \| favorite \| on: When should you use the IN instead of the OR opera... Seems like an obvious optimization to use a hash instead of scanning the array with comparisons... but I bet it's hard because on small arrays sequentially scanning is faster than building a hash first. Does anyone know at what size the optimizer switches from scanning the list to a hash?

angry__panda on Aug 31, 2023 [–]

Based on my experiments, Postgres switches from scanning the list to a hash when the array size > 8.

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