Documentation and test coverage for the size of the ARRAY_AGG() partial state - #4597
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Documentation and test coverage for the size of the ARRAY_AGG() partial state#4597robert-brunel wants to merge 1 commit into
ARRAY_AGG() partial state#4597robert-brunel wants to merge 1 commit into
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…tial state `ARRAY_AGG()` has some inherent caveats around its partial state, which deserve dedicated tests and a note in the SQL Reference. The size of the state is O(N), since it holds every element collected so far, and on a mid-group stop it is serialized into the continuation that is handed to the client. Nothing in either the Record Layer or FDB limits the size. * Document the group-size caveats in the SQL Reference. * Add a block to `array-agg-tests.yamsql` that covers a fairly large group end to end, and a second one that exercises the continuation carrying the partial state. * Add a `partialAggregateArrayAggLargeGroup()` test to pin the per-element cost against a potential blowup, and to check that a group resumed from a mid-group continuation completes with every element present exactly once.
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ARRAY_AGG()comes with inherent caveats around the size of its partial state, which deserve some dedicated tests and a note in the SQL Reference. The size of the state is O(N), since it holds every element collected so far, and on a mid-group stop it is serialized into the continuation that is handed to the client. Nothing in either the Record Layer or FDB limits the size.array-agg-tests.yamsqlthat covers a fairly large group end to end, and a second one that exercises the continuation carrying the partial state.partialAggregateArrayAggLargeGroup()test to pin the per-element cost against a potential blowup, and to check that a group resumed from a mid-group continuation completes with every element present exactly once.