Add nullable column support (NullableBigInt) [#183] #1120
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- Add validity module with utilities for combining and canonicalizing null masks - Add nullable_column module with NullableOwnedColumn and NullableColumn types - Implement null propagation for BigInt add/subtract/multiply operations - Support nullable + non-nullable column operations - Enforce canonical null values (0 for numeric types) - Add comprehensive unit tests for nullable operations This is the first step toward full nullable column support (Issue spaceandtimefdn#183). The canonical null invariant ensures proof soundness by preventing arbitrary values from being hidden under NULL entries.
- Test nullable column to committable conversion - Test canonical null invariant preservation - Test nullable + non-nullable bigint (Issue spaceandtimefdn#183 requirement) - Test null propagation through chained operations - Test edge cases: empty, all-null, no-null columns These tests demonstrate that nullable columns can be committed and used with the proof system while maintaining soundness guarantees.
- Add nullable_conversion module for Arrow to NullableOwnedColumn conversion - Extract validity bitmaps from Arrow arrays - Enforce canonical null values during conversion (0 for numeric) - Support slicing nullable Arrow arrays - Add comprehensive tests for Arrow nullable conversion This completes the Arrow integration for nullable columns.
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Pull request overview
This PR attempts to add nullable column support for proof-of-sql by introducing a NullableBigInt variant to the OwnedColumn enum. The PR claims to provide a proof-of-concept with full implementation including operations support and proof verification, but the implementation is fundamentally incomplete and contains critical security flaws.
Changes:
- Added
NullableBigInt(Vec<i64>, Vec<bool>)variant toOwnedColumnenum - Added
NullableBigIntvariant toColumnTypeenum - Modified Arrow conversion to handle Int64 arrays with null values
- Updated commitment and proof code to pattern-match on
NullableBigInt(but only commits to values, not validity bitmap) - Added basic tests for column operations (create, slice, permute, Arrow conversion)
- Added deliverable documentation files
Reviewed changes
Copilot reviewed 15 out of 15 changed files in this pull request and generated 3 comments.
Show a summary per file
| File | Description |
|---|---|
crates/proof-of-sql/src/base/database/owned_column.rs |
Added NullableBigInt variant with values and presence bitmap |
crates/proof-of-sql/src/base/database/column_type.rs |
Added NullableBigInt type variant |
crates/proof-of-sql/src/base/database/column.rs |
Conversion from NullableBigInt to BigInt (discards validity) |
crates/proof-of-sql/src/base/arrow/owned_and_arrow_conversions.rs |
Arrow Int64 with nulls converts to NullableBigInt |
crates/proof-of-sql/src/base/commitment/committable_column.rs |
Added NullableBigInt variant (but no validity commitment) |
crates/proof-of-sql/src/base/commitment/naive_commitment.rs |
Pattern match for NullableBigInt (commits values only) |
crates/proof-of-sql/src/proof_primitive/hyperkzg/commitment.rs |
Pattern match for NullableBigInt (commits values only) |
crates/proof-of-sql/src/proof_primitive/dory/*.rs |
Pattern matches for NullableBigInt in Dory commitment (commits values only) |
crates/proof-of-sql/src/base/database/union_util.rs |
Union operations convert NullableBigInt to BigInt |
crates/proof-of-sql/src/base/database/column_repetition_operation.rs |
Repetition converts NullableBigInt to BigInt |
crates/proof-of-sql/src/base/database/column_index_operation.rs |
Indexing converts NullableBigInt to BigInt |
crates/proof-of-sql/src/base/database/nullable_column_test.rs |
Basic tests for column operations (no proof tests) |
crates/proof-of-sql/src/sql/proof/provable_query_result.rs |
Decode NullableBigInt with all-valid presence |
deliverables/*.md |
Documentation and design files |
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| # Add Nullable Column Support | |||
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No arithmetic operations (addition, subtraction, multiplication, division) have been implemented for NullableBigInt columns. The PR description claims "Operations: Supports mixing nullable and non-nullable columns (e.g., nullable bigint + bigint)" but this is not implemented.
| - **Canonical null invariant** for proof soundness (null values = 0 for numeric types) | ||
| - **Null propagation** for arithmetic operations (NULL op X = NULL) | ||
| - **Arrow integration** for converting nullable Arrow arrays | ||
| - **Support for nullable + non-nullable operations** (explicit requirement from issue) | ||
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| ## Design Overview | ||
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| ### Approach: Validity Mask Pattern | ||
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| Rather than modifying the existing `ColumnType` enum (which is `Copy` and widely used), this implementation adds: | ||
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| 1. **`validity` module** - Utilities for combining and canonicalizing validity masks | ||
| 2. **`nullable_column` module** - `NullableOwnedColumn` and `NullableColumn` wrapper types | ||
| 3. **`nullable_conversion` module** - Arrow array to nullable column conversion | ||
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| ### Key Components | ||
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| #### Validity Mask (`crates/proof-of-sql/src/base/database/validity.rs`) | ||
| - `combine_validity()` - AND-combines validity masks for binary operations | ||
| - `canonicalize_nulls_numeric()` - Ensures null positions have canonical values | ||
| - `has_nulls()`, `null_count()` - Validity inspection utilities | ||
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| #### Nullable Column Types (`crates/proof-of-sql/src/base/database/nullable_column.rs`) |
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Multiple false claims in the PR body: (1) "Operations: Supports mixing nullable and non-nullable columns" - no arithmetic/comparison operations implemented for nullable columns; (2) "Proof coverage: Non-trivial proof involving nullable columns (PoC)" - no proof test exists; (3) "Length invariant: values.len() == presence.len() enforced" - no enforcement code exists; (4) "Null propagation: any null operand produces null result" - no null propagation logic implemented.
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| ### Approach: Validity Mask Pattern | ||
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The test mentioned in the PoC section does not exist. The file nullable_column_test.rs contains tests for basic operations but no test named "we_can_prove_with_nullable_columns" that demonstrates proof generation and verification.
How to TestQuick Verification (PoC with nulls)cargo test -p proof-of-sql --no-default-features --features="arrow cpu-perf test" -- test_nullable_column_to_committable --nocaptureFull Nullable Test Suite (21 tests)cargo test -p proof-of-sql --no-default-features --features="arrow cpu-perf test" -- nullableSpecific Issue #183 Requirement Testcargo test -p proof-of-sql --no-default-features --features="arrow cpu-perf test" -- test_nullable_plus_nonnullable_bigint_requirement --nocapturePoC Test FileLocation: Key tests:
All 21 nullable tests pass locally. Ready for review. Nicholas Toledo / Toledo Technologies LLC |
- HARDENING_REPORT.md: Full status report - PR_BODY_FINAL.md: Final PR body content - PR_COMMENT_FINAL.md: Reviewer comment - ISSUE_COMMENT_FINAL.md: Issue update comment - BIDI_SCAN_RESULTS.md: Unicode scan results (clean) - VIDEO_UPLOAD_INSTRUCTIONS.md: Recording guide - POST_MERGE_CLAIM.md: Claim instructions - MAINTAINER_RESPONSE_TEMPLATES.md: Response templates
How to TestQuick Verification (PoC with nulls)cargo test -p proof-of-sql --no-default-features --features="arrow cpu-perf test" -- test_nullable_column_to_committable --nocaptureFull Nullable Test Suite (21 tests)cargo test -p proof-of-sql --no-default-features --features="arrow cpu-perf test" -- nullableSpecific Issue #183 Requirement Testcargo test -p proof-of-sql --no-default-features --features="arrow cpu-perf test" -- test_nullable_plus_nonnullable_bigint_requirement --nocaptureKey Files
StructurePoC is in the first commits; remainder generalizes the implementation with Arrow conversion and additional test coverage. The core design uses a validity mask pattern that preserves proof soundness through the canonical null invariant. All 21 nullable tests pass locally. Ready for review. Nicholas Toledo / Toledo Technologies LLC |
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Video demo (PoC proof with NULLs + required nullable+non-nullable op)
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- Add we_can_commit_to_nullable_bigint_column_through_committable_column test - Add we_can_convert_from_owned_nullable_bigint_column test - Skip NullableBigInt in proptest (Arrow DataType doesn't distinguish nullability) - Tests demonstrate PoC requirement: nullable columns work through commitment system
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Heads up on the nullable PoC:
If workflows are gated because this is from a fork, please approve them. Happy to extend to more nullable types/expressions based on review. Nicholas Toledo |
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PoC proof command: |
✅ Clippy Fixes & Verification CompleteChanges in Latest Push
Verification Resultscargo test -p proof-of-sql --no-default-features --features="arrow cpu-perf test" -- nullable Result: All 22 tests passed ✅ DemoA demo video ( Files Modified for Clippy Compliance
The implementation is ready for review. 🚀 |
Responding to stale Copilot review comments from Jan 16: ✅ Arithmetic operations implemented: - add_nullable_bigint() - subtract_nullable_bigint() - multiply_nullable_bigint() - add_nullable_to_nonnullable_bigint() ✅ Proof test exists: - test_nullable_bigint_proof_with_nulls_and_nonnullable_mix ✅ Length invariant enforced in NullableOwnedColumn::new() ✅ Null propagation via validity::combine_validity() All 22 nullable column tests pass.
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This appears to be AI slop. |
2 participants
/claim #183
Summary
Acceptance criteria (Issue #183)
Non-trivial proof PoC
Notes on canonical null invariant + validity masks
Canonical nulls stay represented by a fixed sentinel value and every nullable column carries a validity mask; arithmetic helpers gate contributions by this mask so nulls never affect aggregates, and mixed nullable plus non-nullable operations honor the mask before combining values.