[
https://issues.apache.org/jira/browse/FLINK-33670?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=17791426#comment-17791426
]
Lyn Zhang commented on FLINK-33670:
-----------------------------------
Making "temporary view" as a real "common table expression" in the whole
optimization process is a perfect solution to resolve this issue. It's can be
controlled by sql developers.
I would like to know which stage the CTE feature is currently in.
> Public operators cannot be reused in multi sinks
> ------------------------------------------------
>
> Key: FLINK-33670
> URL: https://issues.apache.org/jira/browse/FLINK-33670
> Project: Flink
> Issue Type: Improvement
> Components: Table SQL / Planner
> Affects Versions: 1.18.0
> Reporter: Lyn Zhang
> Priority: Major
> Attachments: image-2023-11-28-14-31-30-153.png
>
>
> Dear all:
> I find that some public operators cannot be reused when submit a job with
> multi sinks. I have an example as follows:
> {code:java}
> CREATE TABLE source (
> id STRING,
> ts TIMESTAMP(3),
> v BIGINT,
> WATERMARK FOR ts AS ts - INTERVAL '3' SECOND
> ) WITH (...);
> CREATE VIEW source_distinct AS
> SELECT * FROM (
> SELECT *, ROW_NUMBER() OVER w AS row_nu
> FROM source
> WINDOW w AS (PARTITION BY id ORDER BY proctime() ASC)
> ) WHERE row_nu = 1;
> CREATE TABLE print1 (
> id STRING,
> ts TIMESTAMP(3)
> ) WITH('connector' = 'blackhole');
> INSERT INTO print1 SELECT id, ts FROM source_distinct;
> CREATE TABLE print2 (
> id STRING,
> ts TIMESTAMP(3),
> v BIGINT
> ) WITH('connector' = 'blackhole');
> INSERT INTO print2
> SELECT id, TUMBLE_START(ts, INTERVAL '20' SECOND), SUM(v)
> FROM source_distinct
> GROUP BY TUMBLE(ts, INTERVAL '20' SECOND), id; {code}
> !image-2023-11-28-14-31-30-153.png|width=384,height=145!
> I try to check the code, Flink add the rule of CoreRules.PROJECT_MERGE by
> default, This will create different digests of the deduplicate operator and
> finally fail to match same sub plan.
> In real production environment, Reuse same sub plan like deduplicate is more
> worthy than project merge. A good solution is to interrupt the project merge
> crossing shuffle operators in multi sinks cases.
> How did you consider it? Looking forward to your reply.
--
This message was sent by Atlassian Jira
(v8.20.10#820010)
