Feature: dispatch T_CustomScanState in CBDB parallel walkers - #1855
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Feature: dispatch T_CustomScanState in CBDB parallel walkers#1855roseduan wants to merge 3 commits into
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yjhjstz
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Three GP-side walkers used during parallel setup —
EstimateGpParallelDSMEntrySize, InitializeGpParallelWorkers,
InitializeGpParallelDSMEntry — cased on other scan/join states but
skipped T_CustomScanState. A parallel_aware CustomScan therefore
silently under-sized its DSM and failed to attach in workers, with
no diagnostic.
Add T_CustomScanState arms that dispatch to
ExecCustomScan{Estimate,InitializeDSM,InitializeWorker}, gated on
parallel_aware to match the other node types in these switches.
Also handle T_CustomScanState in planstate_walk_kids. Upstream
planstate_tree_walker walks only css->custom_ps for a
CustomScanState; the CBDB walker previously fell through to
default (lefttree/righttree), skipping custom_ps children under
stateful walkers (cdbexplain_*, getMotionState, ...). The new
case walks custom_ps first, then lefttree/righttree if set, with
an Assert that a CustomScanState never populates both — otherwise
the child would be walked twice.
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Pull request overview
Fixes missing T_CustomScanState handling in Cloudberry’s GP-side parallel setup walkers and CBDB’s planstate child-walking logic, and adds a regression test module to exercise parallel-aware CustomScan behavior.
Changes:
- Dispatch
T_CustomScanStatetoExecCustomScan{Estimate,InitializeDSM,InitializeWorker}in CBDB parallel walkers whenparallel_aware. - Teach
planstate_walk_kids()to recurse intoCustomScanState->custom_ps(and then left/right if present, with an assert to prevent double-walk). - Add
parallel_customscantest extension + SQL/expected files and wire it intosrc/test/modules.
Reviewed changes
Copilot reviewed 9 out of 9 changed files in this pull request and generated 3 comments.
Show a summary per file
| File | Description |
|---|---|
| src/backend/executor/execParallel.c | Adds T_CustomScanState dispatch in GP parallel DSM sizing/init/worker init walkers. |
| src/backend/executor/execProcnode.c | Ensures CBDB planstate walker visits CustomScanState->custom_ps children. |
| src/test/modules/Makefile | Adds parallel_customscan to module subdirs. |
| src/test/modules/parallel_customscan/Makefile | New module build + regression target wiring. |
| src/test/modules/parallel_customscan/parallel_customscan.c | New test extension implementing a parallel-aware CustomScan wrapper. |
| src/test/modules/parallel_customscan/parallel_customscan.control | New extension control metadata. |
| src/test/modules/parallel_customscan/parallel_customscan--1.0.sql | New extension SQL defining pcs_get_hook_calls(). |
| src/test/modules/parallel_customscan/sql/parallel_customscan.sql | New regression SQL exercising parallel custom scan + EXPLAIN ANALYZE traversal. |
| src/test/modules/parallel_customscan/expected/parallel_customscan.out | New expected regression output. |
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| @@ -0,0 +1,396 @@ | |||
| #include "postgres.h" | |||
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| # Run against an existing cluster (gpdemo). The cluster must have | ||
| # 'parallel_customscan' in shared_preload_libraries so segment backends | ||
| # and parallel workers have the CustomScan methods registered: | ||
| # gpconfig -c shared_preload_libraries -v "'time_series,parallel_customscan'" | ||
| # gpstop -ra |
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| if (TupIsNull(childslot)) | ||
| return NULL; |
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Three GP-side walkers used during parallel setup — EstimateGpParallelDSMEntrySize, InitializeGpParallelWorkers, InitializeGpParallelDSMEntry — cased on other scan/join states but skipped T_CustomScanState. A parallel_aware CustomScan therefore silently under-sized its DSM and failed to attach in workers, with no diagnostic.
Add T_CustomScanState arms that dispatch to
ExecCustomScan{Estimate,InitializeDSM,InitializeWorker}, gated on parallel_aware to match the other node types in these switches.
Also handle T_CustomScanState in planstate_walk_kids. Upstream planstate_tree_walker walks only css->custom_ps for a CustomScanState; the CBDB walker previously fell through to default (lefttree/righttree), skipping custom_ps children under stateful walkers (cdbexplain_*, getMotionState, ...). The new case walks custom_ps first, then lefttree/righttree if set, with an Assert that a CustomScanState never populates both — otherwise the child would be walked twice.
Fixes #ISSUE_Number
What does this PR do?
Type of Change
Breaking Changes
Test Plan
make installcheckmake -C src/test installcheck-cbdb-parallelImpact
Performance:
User-facing changes:
Dependencies:
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