[FLINK-21465] Extend explain syntax

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Duplicate
• Component/s: Table SQL / API, Table SQL / Client
• Assignee: Unassigned
• Reporter: Shengkai Fang
• Created: 23/Feb/21 10:31
• Updated: 12/Mar/21 06:33
• Resolved: 12/Mar/21 06:32

Description

Allow users to specify the ExplainDetails in statement.

EXPLAIN [ExplainDetail[, ExplainDetail]*] <statement>



ExplainDetail: {

  ESTIMATED_COST,

  CHANGELOG_MODE,

  JSON_EXECUTION_PLAN

}

Print the plan for the statement with specified ExplainDetails.

ESTIMATED_COST
generates cost information on physical node estimated by optimizer, e.g. TableSourceScan(..., cumulative cost =

{1.0E8 rows, 1.0E8 cpu, 2.4E9 io, 0.0 network, 0.0 memory}

)

CHANGELOG_MODE
generates changelog mode for every physical rel node. e.g. GroupAggregate(..., changelogMode=[I,UA,D])

JSON_EXECUTION_PLAN
generates the execution plan in json format of the program.

Flink SQL> EXPLAIN ESTIMATED_COST, CHANGELOG SELECT * FROM MyTable;
...

Issue Links

• is duplicated by: FLINK-20562 Support ExplainDetails for EXPLAIN sytnax