In fact, calcite's rule doesn't care about alias, so it may lose alias when transforming.
Regards! Aron Tao Yanjing Wang <[email protected]> 于2021年11月24日周三 下午2:47写道： > Hi, team > I'm using ProjectRemoveRule to simplify my logical plan, But the plan > sometimes miss its project alias, I find the rule hasn't checked the alias > for project row type identity equation, so I think it may be a bug, I have > tried to reproduce the problem, but I failed to build two projects. > > I have tried the following but the plan always ignores the alias: > > final Function<RelBuilder, RelNode> relFn = b -> { > RelNode plan = b.scan("EMP") > .project( > b.field("DEPTNO"), > b.field("ENAME") > ) > .project( > b.alias(b.field(0), "DEPTNO_ALIAS"), > b.alias(b.field(1), "ENAME_ALIAS") > ) > .build(); > return plan; > }; > > relFn(relFn) > .withRule( > CoreRules.PROJECT_REMOVE) > .withRelBuilderConfig(b -> b.withBloat(-1)) > .check(); > > > So I resort to modifying existing test case to reproduce, I change > the testUnionMergeRule test case in RelOptRulesTest.java. I change its > final projection *** to *name as ename, deptno as edeptno*, > and the plan miss the alias again. I think the hep rules shouldn't remove > the alias which are output column label. >
