[CALCITE-4733] Column names in materialization do not match

• Type: Bug
• Status: Reopened
• Priority: Minor
• Resolution: Unresolved
• Affects Version/s: 1.27.0
• Component/s: core
• Assignee: Unassigned
• Reporter: Enze Liu
• Created: 13/Aug/21 03:16
• Updated: 15/Sep/21 15:02

Description

Original subject: "MaterializedViewAggregateRule should not rewrite top level name alias in project".

We use MaterializedViewAggregateRule to do optimize. 

the original sql is : 

SELECT (intDiv(ts/1000, 60) * 60) * 1000 as t, source_idc, dest_idc, sum(jitter200)/sum(total) as `jitter200_rate` FROM metricsdb.test_table WHERE ts/1000 >= 1627874961 AND source_idc in ('xxx') AND dest_idc IN ('xxx') GROUP BY t,source_idc,dest_idc ORDER BY t

after optimize, the sql is : 

SELECT `intDiv`(`ts` / 1000, 60) * 60 * 1000 AS `$f14`, `source_idc`, `dest_idc`, SUM(`jitter200`) / SUM(`total`) AS `$f3` FROM `metricsdb`.`s2s_idc2idc_jitter_mv_all` WHERE `ts` / 1000 >= 1627874961 AND `source_idc` IN ('xxx') AND `dest_idc` IN ('xxx') GROUP BY `source_idc`, `dest_idc`, `intDiv`(`ts` / 1000, 60) * 60 * 1000 ORDER BY `intDiv`(`ts` / 1000, 60) * 60 * 1000

we expected it to be : 

`intDiv`(`ts` / 1000, 60) * 60 * 1000 AS `t`

, not

`intDiv`(`ts` / 1000, 60) * 60 * 1000 AS `$f14`

 

After examine the code , we found in  rewriteView of MaterializedViewAggregateRule

    return relBuilder
        .project(rewrittenExprs)
        .convert(topRowType, false) // this means do not compare the names.
        .build();

when change it to true, everything goes as expected.

 

I think the rewrite rule should maintain then same type and name , not just type.  

 

If it's true, we can come up with some modification and tests.

Issue Links

• relates to: CALCITE-4772 PushProjector should retain alias when handling RexCall