apache / apache/datafusion

Support ExistenceJoin type in HashJoin

Open
#4,655 0 comments 1 reaction 0 assignees View on GitHub
enhancement
Dominant language
Rust
Stars
9.3k
Forks
2.4k
Avg merge
3d 7h
Merged PRs (30d)
344

Description

**Is your feature request related to a problem or challenge? Please describe what you are trying to do.**
A clear and concise description of what the problem is. Ex. I'm always frustrated when [...]
(This section helps Arrow developers understand the context and *why* for this feature, in addition to the *what*)

```
SELECT t1_id, t1_name from t1 WHERE
t1_id IN (SELECT t2_id FROM t2 where t2_name = 'b') OR
t1_id IN (SELECT t3_id FROM t3 where t3_name = 'c')
````

````
SELECT t1_id, t1_name from t1 WHERE
t1_id IN (SELECT t2_id FROM t2 where t2_name = 'b') OR
t1_name IN (SELECT t2_name FROM t2 where t2_name = 'b')
````

**Describe the solution you'd like**
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**Describe alternatives you've considered**
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**Additional context**
Add any other context or screenshots about the feature request here.

Contributor guide

Open the contributing guide

Research direction

Start by locating the HashJoin implementation and any existing ExistenceJoin handling in DataFusion. Use the two SQL examples as behavioral cases, covering IN subqueries combined with OR and differing key columns; done means these queries are supported and covered by appropriate tests.

Written by the indexing model from the issue text.

Assessment

Tech stack
rust, sql
Domain
backend, databases
Issue type
Feature
Difficulty
4/5
Estimated time
3-5 days
Activity status
Stale
Clarity
Needs clarification
Newbie friendliness
25/100

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