During planning, Calcite only optimize based on the field input refs, if we always keep the alias, there are many cases that can not be promoted. I collected some cases that already tracked by the JIRA issue:
[1] https://issues.apache.org/jira/browse/CALCITE-4037 [2] https://issues.apache.org/jira/browse/CALCITE-3662 [3] https://issues.apache.org/jira/browse/CALCITE-1584 Best, Danny Chan 在 2020年10月21日 +0800 PM2:49，JiaTao Tao <[email protected]>，写道： > Hi fellows > I found in some place, we just call `project(Iterable<? extends RexNode> > nodes) `, but this will lose alias, why don't we try to call > `project(Iterable<? > extends RexNode> nodes, Iterable<String> fieldNames) ` to keep alias? > > Regards! > > Aron Tao
