avamingli opened a new pull request, #1230:
URL: https://github.com/apache/cloudberry/pull/1230
Fix #1229
This commit addresses the scenario where paths have parallel_workers set to
0, but contain subpaths with parallel_workers greater than 0. This case is
valid and enables our CBDB to maximize parallel execution where feasible,
enhancing overall performance in query processing.
```sql
explain(costs off) SELECT * FROM (SELECT AVG(a) as a FROM dml_union_r UNION
SELECT AVG(b) as a FROM dml_union_s) foo;
QUERY PLAN
-----------------------------------------------------------------------
Unique
Group Key: (avg(dml_union_r.a))
-> Sort
Sort Key: (avg(dml_union_r.a))
-> Append
-> Finalize Aggregate
-> Gather Motion 6:1 (slice1; segments: 6)
-> Partial Aggregate
-> Parallel Seq Scan on dml_union_r
-> Finalize Aggregate
-> Gather Motion 6:1 (slice2; segments: 6)
-> Partial Aggregate
-> Parallel Append
-> Seq Scan on
dml_union_s_1_prt_3 dml_union_s_2
-> Seq Scan on
dml_union_s_1_prt_4 dml_union_s_3
-> Seq Scan on
dml_union_s_1_prt_5 dml_union_s_4
-> Seq Scan on
dml_union_s_1_prt_6 dml_union_s_5
-> Seq Scan on
dml_union_s_1_prt_7 dml_union_s_6
-> Seq Scan on
dml_union_s_1_prt_8 dml_union_s_7
-> Seq Scan on
dml_union_s_1_prt_9 dml_union_s_8
-> Seq Scan on
dml_union_s_1_prt_10 dml_union_s_9
-> Seq Scan on
dml_union_s_1_prt_11 dml_union_s_10
-> Parallel Seq Scan on
dml_union_s_1_prt_2 dml_union_s_1
-> Parallel Seq Scan on
dml_union_s_1_prt_def dml_union_s_11
Optimizer: Postgres query optimizer
(25 rows)
```
Authored-by: Zhang Mingli [email protected]
<!-- Thank you for your contribution to Apache Cloudberry (Incubating)! -->
### What does this PR do?
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### Type of Change
- [ ] Bug fix (non-breaking change)
- [ ] New feature (non-breaking change)
- [ ] Breaking change (fix or feature with breaking changes)
- [ ] Documentation update
### Breaking Changes
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### Test Plan
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- [ ] Unit tests added/updated
- [ ] Integration tests added/updated
- [ ] Passed `make installcheck`
- [ ] Passed `make -C src/test installcheck-cbdb-parallel`
### Impact
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**User-facing changes:**
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**Dependencies:**
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### Checklist
- [ ] Followed [contribution
guide](https://cloudberry.apache.org/contribute/code)
- [ ] Added/updated documentation
- [ ] Reviewed code for security implications
- [ ] Requested review from [cloudberry
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