Brachi Packter created CALCITE-6357: ---------------------------------------
Summary: Calcite enforces select argument count to be same as row schema fields which causes aliases to be ignored Key: CALCITE-6357 URL: https://issues.apache.org/jira/browse/CALCITE-6357 Project: Calcite Issue Type: Bug Reporter: Brachi Packter Calcite RelBuilder.ProjectNamed cehcks if row size in the select is identical to schema fields, if no, it creates a project with fields as they appear in the select , meaning if they have aliases, they are returning with their aliases. Here it checks if they are identical: https://github.com/apache/calcite/blob/f14cf4c32b9079984a988bbad40230aa6a59b127/core/src/main/java/org/apache/calcite/tools/RelBuilder.java#L2063 using RexUtil.isIdentity method: ``` public static boolean isIdentity(List<? extends RexNode> exps, RelDataType inputRowType) { return inputRowType.getFieldCount() == exps.size() && containIdentity(exps, inputRowType, Litmus.IGNORE); } ``` This is the problematic part `inputRowType.getFieldCount() == exps.size()` And then it is ignored in the "rename" method later on https://github.com/apache/calcite/blob/f14cf4c32b9079984a988bbad40230aa6a59b127/core/src/main/java/org/apache/calcite/tools/RelBuilder.java#L2125 and alias is skipped https://github.com/apache/calcite/blob/f14cf4c32b9079984a988bbad40230aa6a59b127/core/src/main/java/org/apache/calcite/tools/RelBuilder.java#L2137 This doesn't impact calcite queries, but in Apache Beam they are doing some optimization on top of it, https://github.com/apache/beam/blob/master/sdks/java/extensions/sql/src/main/java/org/apache/beam/sdk/extensions/sql/impl/rule/BeamAggregateProjectMergeRule.java which cause aliases to be ignored, and data is returning suddenly without correct column field. I believe the isIdentity check can causes more issues if not fixed, we need to understand why is it enforced? isn't it valid to have different size of fields in select from what we have in the schema? In our case we have a one big row and we run on it different queries, each with different fields in the select. Beam issue https://github.com/apache/beam/issues/30498 -- This message was sent by Atlassian Jira (v8.20.10#820010)