---
phase: 19-parser-hook-validation-spike
plan: 01
subsystem: database
tags: [duckdb, parser-hook, ddl, spike, scope-decision]

# Dependency graph
requires:
  - phase: 18-verification-and-integration
    provides: Parser hook infrastructure (CREATE SEMANTIC VIEW via sv_parse_rust)
provides:
  - Empirical proof that all 7 DDL prefixes trigger the parser fallback hook
  - Scope decision document for v0.5.1 native DDL coverage
  - Prefix overlap finding (CREATE SEMANTIC VIEW IF NOT EXISTS)
affects: [20-extended-ddl-statements, 21-error-location-reporting]

# Tech tracking
tech-stack:
  added: []
  patterns: [prefix-ordering-in-detection, empirical-spike-validation]

key-files:
  created:
    - test/sql/phase19_parser_hook_validation.test
    - .planning/phases/19-parser-hook-validation-spike/19-SPIKE-RESULTS.md
  modified:
    - test/sql/TEST_LIST

key-decisions:
  - "All 7 DDL prefixes trigger parser fallback hook -- full native DDL scope for v0.5.1"
  - "Phase 20 detection must check longer prefixes first to avoid prefix overlap"

patterns-established:
  - "Prefix ordering: longer prefixes checked before shorter ones in multi-prefix detection"
  - "Empirical spike pattern: sqllogictest + SPIKE-RESULTS.md before implementation phase"

requirements-completed: []

# Metrics
duration: 7min
completed: 2026-03-09
---

# Phase 19 Plan 01: Parser Hook Validation Spike Summary

**All 7 DDL prefixes empirically confirmed to trigger parser fallback hook; full native DDL scope approved for v0.5.1**

## Performance

- **Duration:** 7 min
- **Started:** 2026-03-09T11:01:44Z
- **Completed:** 2026-03-09T11:09:00Z
- **Tasks:** 2
- **Files modified:** 3

## Accomplishments
- Proved all 7 DDL prefixes produce Parser Errors (not Catalog/Binder Errors), confirming the fallback hook path is reachable
- Discovered and documented the prefix overlap case: `CREATE SEMANTIC VIEW IF NOT EXISTS` matches the existing shorter prefix, creating a view named "IF"
- Documented concrete scope decision: all DDL statements get native syntax in v0.5.1

## Task Commits

Each task was committed atomically:

1. **Task 1: Create sqllogictest validating all 7 DDL prefixes trigger parser errors** - `35b0941` (test)
2. **Task 2: Document spike results and scope decision** - `27c193c` (docs)

## Files Created/Modified
- `test/sql/phase19_parser_hook_validation.test` - Sqllogictest proving all 7 DDL prefixes produce Parser Errors
- `test/sql/TEST_LIST` - Added new test file to test runner file list
- `.planning/phases/19-parser-hook-validation-spike/19-SPIKE-RESULTS.md` - Empirical results table, analysis, and scope decision

## Decisions Made
- **Full native DDL scope for v0.5.1:** All 7 DDL prefixes confirmed to trigger the parser fallback hook. No statements need function-only fallback.
- **Prefix ordering required for Phase 20:** Detection function must check longer prefixes first (`CREATE OR REPLACE SEMANTIC VIEW` before `CREATE SEMANTIC VIEW`) to prevent the prefix overlap demonstrated by the spike.

## Deviations from Plan

None -- plan executed exactly as written.

## Issues Encountered
None.

## User Setup Required
None -- no external service configuration required.

## Next Phase Readiness
- Phase 20 (Extended DDL Statements) can proceed with full native DDL coverage for DDL-03 through DDL-08
- Prefix ordering guidance documented in SPIKE-RESULTS.md for the detection function implementation
- P3 blocker (three-connection lock conflict during DROP) should be tested early in Phase 20

## Self-Check: PASSED

- FOUND: test/sql/phase19_parser_hook_validation.test
- FOUND: .planning/phases/19-parser-hook-validation-spike/19-SPIKE-RESULTS.md
- FOUND: .planning/phases/19-parser-hook-validation-spike/19-01-SUMMARY.md
- FOUND: commit 35b0941
- FOUND: commit 27c193c

---
*Phase: 19-parser-hook-validation-spike*
*Completed: 2026-03-09*
