Adding support for DML writes to DV enabled tables - #15869
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Greptile SummaryThis PR adds GPU acceleration for DELETE, UPDATE, and MERGE against Delta tables using deletion vectors while retaining Delta’s transaction and DV serialization paths on the CPU.
Confidence Score: 5/5The PR appears safe to merge because no blocking failure remains in the eligible follow-up review scope. No blocking failure remains. Important Files Changed
Flowchart%%{init: {'theme': 'neutral'}}%%
flowchart LR
A[Delta DELETE / UPDATE / MERGE] --> B[GPU candidate-file scan]
B --> C[Apply existing deletion vectors]
C --> D[Preserve physical row indexes]
D --> E[GPU predicate, join, and aggregation work]
E --> F[Group modified indexes by source file]
F --> G[CPU bitmap and DV serialization]
G --> H[Delta action construction]
H --> I[Optimistic transaction commit]
Reviews (3): Last reviewed commit: "Fix build errors" | Re-trigger Greptile |
Signed-off-by: Rahul Prabhu <raprabhu@nvidia.com>
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Fixes #12577.
Description
This PR adds GPU acceleration for Apache Delta Lake DELETE, UPDATE, and MERGE commands on deletion vector enabled tables.
With deletion vectors, existing Parquet rows are logically removed by recording their physical row indexes in a DV. Updated or inserted rows are written to new Parquet files. This PR accelerates the data intensive parts of that workflow on the GPU while retaining Delta’s existing transaction and deletion vector semantics.
Implementation
The implementation accelerates:
MERGE.Collision free dictionary IDs are used in GPU aggregations instead of carrying full file paths or relying on hashes. This reduces GPU memory and shuffle overhead while preserving an exact mapping back to each Delta
AddFile.Candidate files that already have deletion vectors are also supported. The GPU scan returns physical row indexes after applying the existing DV, and newly modified positions are combined with the existing deleted positions before the updated DV is written.
Sparse RoaringBitmap construction, DV serialization, Delta action construction, and optimistic transaction commit remain on the CPU. These are relatively smaller operations compared to the larger scans, joins, aggregations, and Parquet writes that remain GPU accelerated.
Performance
Performance was measured on the Spark2A A100 cluster using Spark 3.5.7 and Delta Lake 3.3.1.
The benchmark used approximately 365 days of the SF3000 NDS
store_salesdataset. Deterministic predicates modified approximately 10% of the target rows. Each command was measured using five independent CPU runs and five independent GPU runs, with zero warmup iterations and cluster reuse.Checklists
Documentation
Testing
(Please provide the names of the existing tests in the PR description.)
Performance