[FLINK-19108] Stop expanding the identifiers with scope aliased by the system with 'EXPR$' prefix

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 1.12.0, 1.11.2
• Fix Version/s: 1.11.2
• Component/s: Table SQL / API
• Labels: pull-request-available
• Assignee: Danny Chen
• Reporter: Danny Chen
• Created: 01/Sep/20 07:18
• Updated: 04/Sep/20 05:53
• Resolved: 04/Sep/20 05:53

Description

For query

create view tmp_view as
select * from (
  select f0,
  row_number() over (partition by f0 order by f0 desc) as rowNum
  from source) -- the query would be aliased as "EXPR$1"
  where rowNum = 1

When validation, the inner query would have alias assigned by the system with prefix "EXPR$1", when in the `Expander`, we replace the id in the inner query all with this prefix which is wrong because we do not add the alias to the inner query anymore.

To solve the problem, skip the expanding of id with "EXPR$" just like how SqlUtil#deriveAliasFromOrdinal added it.

This was introduced by FLINK-18750.

Issue Links

• is caused by: FLINK-18750 SqlValidatorException thrown when select from a view which contains a UDTF call
• links to: GitHub Pull Request #13293