Support unparsing UNNEST plan to UNNEST table factor SQL
#13660
Conversation
| sql: "SELECT UNNEST([1,2,3])", | ||
| expected: r#"SELECT * FROM UNNEST([1, 2, 3])"#, |
There was a problem hiding this comment.
Because the logical plan of SELECT UNNEST([1,2,3]) and SELECT * FROM UNNEST([1, 2, 3]) is the same, if the with_unnest_as_table_factor is enabled, we can't avoid to unparse it to the table factor SQL. However, I guess it's fine because they are the same in most scenarios. 🤔
| /// Allow to unparse the unnest plan as [ast::TableFactor::UNNEST]. | ||
| /// | ||
| /// Some dialects like BigQuery require UNNEST to be used in the FROM clause but | ||
| /// the LogicalPlan planner always put UNNEST in the SELECT clause. This flag allows |
There was a problem hiding this comment.
put -> puts
well, UNNEST is a lateral relational operator. It doesn't belong to the select clause.
It's probably yet another witness of the problem that the LP is half way between AST and a good IR (which we don't have yet)
There was a problem hiding this comment.
well, UNNEST is a lateral relational operator. It doesn't belong to the select clause. It's probably yet another witness of the problem that the LP is half way between AST and a good IR (which we don't have yet)
Interesting.
The logical planner plans FROM unnest([1,2,3]) to
Projection: unnest_placeholder(make_array(Int64(1),Int64(2),Int64(3)),depth=1) AS UNNEST(make_array(Int64(1),Int64(2),Int64(3)))
Unnest: lists[unnest_placeholder(make_array(Int64(1),Int64(2),Int64(3)))|depth=1] structs[]
Projection: make_array(Int64(1), Int64(2), Int64(3)) AS unnest_placeholder(make_array(Int64(1),Int64(2),Int64(3)))
EmptyRelation
Do you think it's a good plan? What would a good IR look like? 🤔
There was a problem hiding this comment.
It's not unreasonable.
Looking at this the "unnest_placeholder" looks more like "unnest input".
There was a problem hiding this comment.
actually it's both: unnest input and unnest output. confusing.
|
Thanks @findepi for reviewing 👍 |
|
🚀 |
…13660) * add `unnest_as_table_factor` and `UnnestRelationBuilder` * unparse unnest as table factor * fix typo * add tests for the default configs * add a static const for unnest_placeholder * fix tests * fix tests
…13660) * add `unnest_as_table_factor` and `UnnestRelationBuilder` * unparse unnest as table factor * fix typo * add tests for the default configs * add a static const for unnest_placeholder * fix tests * fix tests
Which issue does this PR close?
Closes #13601
Rationale for this change
What changes are included in this PR?
Are these changes tested?
Are there any user-facing changes?