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Wang Weidong updated CALCITE-3466: ---------------------------------- Description: While convert RelNode to SqlNode, the "group by" statement in subquery was dropped unexpectedly. For example, original sql is: {code:sql} select a, avg(c1) from ( select a,sum(d),b as c1 from t group by b,a ) as t group by a {code} RelNode converted by SqlNode is {code:sql} LogicalAggregate(group=[{0}], EXPR$1=[AVG($1)]) LogicalProject(A=[$1], C1=[$0]) LogicalAggregate(group=[{0, 1}], EXPR$1=[SUM($2)]) LogicalProject(B=[$1], A=[$0], D=[$3]) EnumerableTableScan(table=[[T_TESTPROJECTMERGE]]) {code} And then convert this RelNode to SqlNode, the sql of SqlNode is like this: {code:sql} SELECT `A`, AVG(`B`) FROM `T` GROUP BY `A` {code} We can find that "group by" in subquery was dropped which may cause SqlNode converted by RelNode being not equivalent to RelNode. After debugging, I've found code at https://github.com/apache/calcite/blob/aa98c1575762718b238af8ddd44a390607de7602/core/src/main/java/org/apache/calcite/rel/rel2sql/RelToSqlConverter.java#L333 calls org.apache.calcite.rel.rel2sql.SqlImplementor.Builder#setGroupBy without judge whether "group by" already exists. Finally, I think in this case, the main select and sub-select shouldn't be merged. was: While convert RelNode to SqlNode, the "group by" statement in subquery was dropped unexpectedly. For example, original sql is: {code:sql} select a, avg(c1) from ( select a,sum(d),b as c1 from t group by b,a ) as t group by a {code} RelNode converted by SqlNode is {code:sql} LogicalAggregate(group=[{0}], EXPR$1=[AVG($1)]) LogicalProject(A=[$1], C1=[$0]) LogicalAggregate(group=[{0, 1}], EXPR$1=[SUM($2)]) LogicalProject(B=[$1], A=[$0], D=[$3]) EnumerableTableScan(table=[[T_TESTPROJECTMERGE]]) {code} And then convert this RelNode to SqlNode, the sql of SqlNode is like this: {code:sql} SELECT `A`, AVG(`B`) FROM `T` GROUP BY `A` {code} We can find that "group by" in subquery was dropped which may cause SqlNode converted by RelNode being not equivalent to RelNode. > JDBC adapter dropped group by statement in subquery > --------------------------------------------------- > > Key: CALCITE-3466 > URL: https://issues.apache.org/jira/browse/CALCITE-3466 > Project: Calcite > Issue Type: Bug > Components: core > Affects Versions: 1.21.0, 1.22.0 > Reporter: Wang Weidong > Priority: Major > Fix For: 1.22.0 > > > While convert RelNode to SqlNode, the "group by" statement in subquery was > dropped unexpectedly. For example, > original sql is: > {code:sql} > select a, avg(c1) from > ( > select a,sum(d),b as c1 from t group by b,a > ) as t > group by a > {code} > RelNode converted by SqlNode is > {code:sql} > LogicalAggregate(group=[{0}], EXPR$1=[AVG($1)]) > LogicalProject(A=[$1], C1=[$0]) > LogicalAggregate(group=[{0, 1}], EXPR$1=[SUM($2)]) > LogicalProject(B=[$1], A=[$0], D=[$3]) > EnumerableTableScan(table=[[T_TESTPROJECTMERGE]]) > {code} > And then convert this RelNode to SqlNode, the sql of SqlNode is like this: > {code:sql} > SELECT `A`, AVG(`B`) > FROM `T` > GROUP BY `A` > {code} > We can find that "group by" in subquery was dropped which may cause SqlNode > converted by RelNode being not equivalent to RelNode. > After debugging, I've found code > at > https://github.com/apache/calcite/blob/aa98c1575762718b238af8ddd44a390607de7602/core/src/main/java/org/apache/calcite/rel/rel2sql/RelToSqlConverter.java#L333 > > calls org.apache.calcite.rel.rel2sql.SqlImplementor.Builder#setGroupBy > without judge whether "group by" already exists. > Finally, I think in this case, the main select and sub-select shouldn't be > merged. -- This message was sent by Atlassian Jira (v8.3.4#803005)