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Aleksey Plekhanov commented on IGNITE-15993: -------------------------------------------- [~vladsz83], thanks for the review! Merged to sql-calcite branch. > Calcite engine. Wrong result for single-value aggregation from empty source > --------------------------------------------------------------------------- > > Key: IGNITE-15993 > URL: https://issues.apache.org/jira/browse/IGNITE-15993 > Project: Ignite > Issue Type: Bug > Reporter: Aleksey Plekhanov > Assignee: Vladimir Steshin > Priority: Minor > Labels: calcite2-required, calcite3-required > Time Spent: 20m > Remaining Estimate: 0h > > For example: > {noformat} > SELECT (SELECT 1 FROM (SELECT 1) WHERE 1 = 0) > {noformat} > Returns 0, but expected {{{}NULL{}}}. > With correlated queries result even more strange: > {noformat} > CREATE TABLE test (a INTEGER) > INSERT INTO test VALUES (1), (2), (null) > SELECT (SELECT 1 FROM test t WHERE a = test.a) FROM test > {noformat} > Returns 1, 1, 1 (expected 1, 1, NULL) > Related test {{test_correlated_subquery.test_ignore}} > From SQL standard: > {noformat} > Let SS be a <scalar subquery>. > Case: > a) If the cardinality of SS is greater than 1 (one), then an exception > condition is raised: cardinality violation. > b) If the cardinality of SS is 0 (zero), then the value of the <scalar > subquery> is the null value. > c) Otherwise, let C be the column of <query expression> simply contained in > SS. The value of SS is the value of C in the unique row of the result of the > <scalar subquery>.{noformat} -- This message was sent by Atlassian Jira (v8.20.1#820001)