[fix](hist) Fix unstable result of aggregrate function hist #38608 #38893
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…8608) * Target Fix unstable result of hist function when involving null value. * Reproduce test result of `regression-test/suites/query_p0/sql_functions/aggregate_functions/test_aggregate_all_functions2.groovy` is unstable, sql `SELECT histogram(k7, 5) FROM baseall` will sometimes acts like the second argument is not passed in. * Root reason We have short-circuit in AggregateFunctionNullVariadicInline, when this row is NULL, the value will not be added by the nested function. Implementation of histogram relies on its add method to get its seconds argument, when we have an all null value block, histogram will not get its seconds arg even if sql is like `select(k7, 5)`, so a max_bucket_num with default value 128 is serialized. When we do merging, and happens to deserialize the above block at last, the max_bucket_num in merge stage will be assigned to 128, and this leads to the wrong result. * Fix by Init value of max_bucket_num is assigned to 0, when we do merging, we will discard this aggregated data if its max_bucket_num is 0.
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run buildall |
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Thank you for your contribution to Apache Doris. Since 2024-03-18, the Document has been moved to doris-website. |
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clang-tidy review says "All clean, LGTM! 👍" |
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TeamCity be ut coverage result: |
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cherry pick from #38608