[FLINK-22113][table-planner-blink] Implement the column uniqueness checking for TableSourceTable

[xuguangheng]

What is the purpose of the change

Implement the column uniqueness checking to avoid losing uniqueness information during join operations.

More specifically,

CREATE TEMPORARY TABLE passengers (
  passenger_key STRING,
  PRIMARY KEY (passenger_key) NOT ENFORCED
) WITH (
  'connector' = 'values'
)

CREATE TEMPORARY TABLE booking_channels (
  booking_channel_key STRING,
  PRIMARY KEY (booking_channel_key) NOT ENFORCED
) WITH (
  'connector' = 'values'
)

CREATE TEMPORARY TABLE train_activities (
  passenger_key STRING,
  booking_channel_key STRING,
  PRIMARY KEY (booking_channel_key) NOT ENFORCED
) WITH (
  'connector' = 'values'
)

SELECT t.booking_channel_key as booking_channel_key, t.passenger_key as passenger_key, b.booking_channel_key as booking_channel_key_0
FROM train_activities t
LEFT JOIN booking_channels b
ON t.booking_channel_key = b.booking_channel_key
LEFT JOIN passengers p
on t.passenger_key = p.passenger_key

== Optimized Physical Plan ==
Calc(select=[booking_channel_key, passenger_key, booking_channel_key0 AS booking_channel_key_0])
+- Join(joinType=[LeftOuterJoin], where=[=(passenger_key, passenger_key0)], select=[passenger_key, booking_channel_key, booking_channel_key0, passenger_key0], leftInputSpec=[HasUniqueKey], rightInputSpec=[JoinKeyContainsUniqueKey])
   :- Exchange(distribution=[hash[passenger_key]])
   :  +- Join(joinType=[LeftOuterJoin], where=[=(booking_channel_key, booking_channel_key0)], select=[passenger_key, booking_channel_key, booking_channel_key0], leftInputSpec=[JoinKeyContainsUniqueKey], rightInputSpec=[JoinKeyContainsUniqueKey])
   :     :- Exchange(distribution=[hash[booking_channel_key]])
   :     :  +- TableSourceScan(table=[[default_catalog, default_database, train_activities]], fields=[passenger_key, booking_channel_key])
   :     +- Exchange(distribution=[hash[booking_channel_key]])
   :        +- TableSourceScan(table=[[default_catalog, default_database, booking_channels]], fields=[booking_channel_key])
   +- Exchange(distribution=[hash[passenger_key]])
      +- TableSourceScan(table=[[default_catalog, default_database, passengers]], fields=[passenger_key])

VS

SELECT t.booking_channel_key as booking_channel_key, t.passenger_key as passenger_key
FROM train_activities t
LEFT JOIN booking_channels b
ON t.booking_channel_key = b.booking_channel_key
LEFT JOIN passengers p
on t.passenger_key = p.passenger_key


== Optimized Physical Plan ==
Calc(select=[booking_channel_key, passenger_key])
+- Join(joinType=[LeftOuterJoin], where=[=(passenger_key, passenger_key0)], select=[passenger_key, booking_channel_key, passenger_key0], leftInputSpec=[NoUniqueKey], rightInputSpec=[JoinKeyContainsUniqueKey])
   :- Exchange(distribution=[hash[passenger_key]])
   :  +- Calc(select=[passenger_key, booking_channel_key])
   :     +- Join(joinType=[LeftOuterJoin], where=[=(booking_channel_key, booking_channel_key0)], select=[passenger_key, booking_channel_key, booking_channel_key0], leftInputSpec=[JoinKeyContainsUniqueKey], rightInputSpec=[JoinKeyContainsUniqueKey])
   :        :- Exchange(distribution=[hash[booking_channel_key]])
   :        :  +- TableSourceScan(table=[[default_catalog, default_database, train_activities]], fields=[passenger_key, booking_channel_key])
   :        +- Exchange(distribution=[hash[booking_channel_key]])
   :           +- TableSourceScan(table=[[default_catalog, default_database, booking_channels]], fields=[booking_channel_key])
   +- Exchange(distribution=[hash[passenger_key]])
      +- TableSourceScan(table=[[default_catalog, default_database, passengers]], fields=[passenger_key])

 

The only difference is that we select booking_channel_key from both left and right table in the first case and only booking_channel_key from left table in the second case. The result is one has uniqueKey and the other doesn't.

 
t.booking_channel_key, t.passenger_key can be the unique key of the first join output, but it seems we lost this unique information.

Brief change log

• Implement the column uniqueness checking for TableSourceTable
• Add some test cases of uniqueness checking and getUniqueKey for TableSourceTable

Verifying this change

Existing and added test cases, manually rerun the example above and the uniqueness information was remained successfully.

Does this pull request potentially affect one of the following parts:

• Dependencies (does it add or upgrade a dependency): no
• The public API, i.e., is any changed class annotated with @Public(Evolving): no
• The serializers: no
• The runtime per-record code paths (performance sensitive): no
• Anything that affects deployment or recovery: JobManager (and its components), Checkpointing, Kubernetes/Yarn/Mesos, ZooKeeper: no
• The S3 file system connector: no

Documentation

• Does this pull request introduce a new feature? no
• If yes, how is the feature documented? not documented

[flinkbot]

Thanks a lot for your contribution to the Apache Flink project. I'm the @flinkbot. I help the community
to review your pull request. We will use this comment to track the progress of the review.

Automated Checks

Last check on commit ce101bd (Sun Apr 25 03:40:03 UTC 2021)

Warnings:

• No documentation files were touched! Remember to keep the Flink docs up to date!

_{Mention the bot in a comment to re-run the automated checks.}

Review Progress

• ❓ 1. The [description] looks good.
• ❓ 2. There is [consensus] that the contribution should go into to Flink.
• ❓ 3. Needs [attention] from.
• ❓ 4. The change fits into the overall [architecture].
• ❓ 5. Overall code [quality] is good.

Please see the Pull Request Review Guide for a full explanation of the review process.

The Bot is tracking the review progress through labels. Labels are applied according to the order of the review items. For consensus, approval by a Flink committer of PMC member is required

Bot commands

The @flinkbot bot supports the following commands:

• @flinkbot approve description to approve one or more aspects (aspects: description, consensus, architecture and quality)
• @flinkbot approve all to approve all aspects
• @flinkbot approve-until architecture to approve everything until architecture
• @flinkbot attention @username1 [@username2 ..] to require somebody's attention
• @flinkbot disapprove architecture to remove an approval you gave earlier

[flinkbot]

CI report:

• ce101bd Azure: SUCCESS

Bot commands

The @flinkbot bot supports the following commands:

• @flinkbot run azure re-run the last Azure build

[matriv]

@xuguangheng Thank you for your effort!

• Overall it looks good, please rebase with master to get the new layout of the modules
• Please replace the deprecated getSchema()-TableSchema with getUnresolvedSchema()-Schema

[matriv]

Hi @xuguangheng, apologies for the delay in looking at your PR.
We would like to fix this bug soon, as it's a quite important one, would you have the time to continue this PR soon?

[godfreyhe]

Thanks for the contribution @xuguangheng , and so sorry for the late response

[godfreyhe]

The logic is wrong when parts of primary keys are projected. please refer to FlinkRelMdUniqueKeys#getTableUniqueKeys(RelOptTable) to correct the logic

[godfreyhe]

Is there any progress here? @xuguangheng

[matriv]

@xuguangheng Again, apologies for the delay, but since we'd like to get forward and fix this soon, I'd like to take over, I hope that's fine for you.

[xuguangheng]

Thanks for taking over.

[godfreyhe]

close it with: superseded by #17962