xzh_dz created CALCITE-4803: ------------------------------- Summary: RelNode lost alias after remove Project operator Key: CALCITE-4803 URL: https://issues.apache.org/jira/browse/CALCITE-4803 Project: Calcite Issue Type: Improvement Reporter: xzh_dz
In my project, I often use `RelOptRule` to optimize relational algebra. In the process of materialized view optimization, after removing the `Project operator`, I found that RelNode lost its alias and their relational algebra is not equivalent.Examples can be reproduced as follows. {code:java} // code placeholder org.apache.calcite.test.SqlToRelConverterTest @Test void testLoseAlias() { final String sql = "select ename as e, deptno as d, count(distinct empno) from emp group by ename, deptno"; final RelNode rel = tester.convertSqlToRel(sql).rel; // LogicalAggregate(group=[{0, 1}], EXPR$2=[COUNT(DISTINCT $2)]) // LogicalProject(E=[$1], D=[$7], EMPNO=[$0]) // LogicalTableScan(table=[[CATALOG, SALES, EMP]]) System.out.println(RelOptUtil.toString(rel)); final HepProgramBuilder programBuilder = HepProgram.builder(); programBuilder.addRuleInstance(CoreRules.AGGREGATE_PROJECT_MERGE); final HepPlanner planner = new HepPlanner(programBuilder.build()); planner.setRoot(rel); final RelNode relOpt = planner.findBestExp(); //LogicalAggregate(group=[{1, 7}], EXPR$2=[COUNT(DISTINCT $0)]) // LogicalTableScan(table=[[CATALOG, SALES, EMP]]) System.out.println(RelOptUtil.toString(relOpt)); // [ENAME, DEPTNO, EXPR$2] System.out.println(relOpt.getRowType().getFieldNames()); } {code} -- This message was sent by Atlassian Jira (v8.3.4#803005)