Fix planning for CASE-filtered SUM with ELSE 0.#19063
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gianm wants to merge 1 commit intoapache:masterfrom
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Fix planning for CASE-filtered SUM with ELSE 0.#19063gianm wants to merge 1 commit intoapache:masterfrom
gianm wants to merge 1 commit intoapache:masterfrom
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Fixes apache#17768. Previously, when "extendedFilteredSumRewrite: true" (the default), the aggregator SUM(CASE WHEN COND THEN COL1 ELSE 0 END) would be planned into SUM(COL1) FILTER(WHERE COND). This creates a discrepancy in the situation where the underlying relation is nonempty but COND does not match any rows: SQL standard behavior is for the aggregator to return zero, but we returned NULL. This patch fixes it by wrapping such aggregators in COALESCE(_, CASE WHEN COUNT(*) > 0 THEN 0 END).
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Fixes #17768.
Previously, when
extendedFilteredSumRewrite: true(the default), the aggregatorSUM(CASE WHEN COND THEN COL1 ELSE 0 END)would be planned intoSUM(COL1) FILTER(WHERE COND). This creates a discrepancy in the situation where the underlying relation is nonempty but COND does not match any rows: SQL standard behavior is for the aggregator to return zero, but we returned NULL.This patch fixes it by wrapping such aggregators in
COALESCE(_, CASE WHEN COUNT(*) > 0 THEN 0 END).