---
phase: 45-alter-comment-get-ddl
verified: 2026-04-11T22:10:50Z
status: passed
score: 9/9 must-haves verified
re_verification: false
---

# Phase 45: ALTER COMMENT + GET_DDL Verification Report

**Phase Goal:** Users can modify view-level comments after creation and reconstruct re-executable DDL from stored definitions
**Verified:** 2026-04-11T22:10:50Z
**Status:** passed
**Re-verification:** No — initial verification

## Goal Achievement

### Observable Truths

| # | Truth | Status | Evidence |
|---|-------|--------|----------|
| 1 | ALTER SEMANTIC VIEW v SET COMMENT = 'text' changes the view-level comment and is visible in SHOW/DESCRIBE | VERIFIED | `alter_comment_impl` performs catalog read-modify-write via `catalog_upsert`; sqllogictest Case 1 in phase45_alter_comment.test queries `list_semantic_views()` and `describe_semantic_view()` and confirms updated comment |
| 2 | ALTER SEMANTIC VIEW v UNSET COMMENT removes the view-level comment | VERIFIED | `AlterUnsetCommentVTab` sets `def.comment = None`; sqllogictest Case 3 verifies NULL in `list_semantic_views()` after UNSET |
| 3 | GET_DDL('SEMANTIC_VIEW', 'name') returns a valid CREATE OR REPLACE SEMANTIC VIEW statement | VERIFIED | `render_create_ddl` produces `CREATE OR REPLACE SEMANTIC VIEW {name}` header; `GetDdlScalar` VScalar registered; phase45_get_ddl.test Cases 1-5 verify output format |
| 4 | GET_DDL output round-trips correctly: executing the output DDL produces an equivalent definition | VERIFIED | phase45_get_ddl.test Case 6 creates a view, stores GET_DDL output, drops the view, re-executes the DDL, calls GET_DDL again, and asserts equality of both outputs |

**Score:** 4/4 roadmap success criteria verified

### Plan 45-01 Must-Have Truths

| # | Truth | Status | Evidence |
|---|-------|--------|----------|
| 1 | ALTER SEMANTIC VIEW v SET COMMENT = 'text' changes the view-level comment | VERIFIED | `alter_comment_impl` in alter.rs:212; VTab bind reads existing JSON, sets `def.comment = Some(comment)`, persists, upserts catalog |
| 2 | ALTER SEMANTIC VIEW v UNSET COMMENT removes the view-level comment | VERIFIED | `AlterUnsetCommentVTab` calls `alter_comment_impl(state, name, None)` |
| 3 | ALTER SEMANTIC VIEW IF EXISTS nonexistent SET COMMENT = 'x' is a silent no-op | VERIFIED | `if state.if_exists { return Ok("no-op") }` at alter.rs:225; sqllogictest Test 5 |
| 4 | ALTER SEMANTIC VIEW IF EXISTS nonexistent UNSET COMMENT is a silent no-op | VERIFIED | Same guard path; sqllogictest Test 6 |
| 5 | Changed/removed comments are visible in subsequent SHOW SEMANTIC VIEWS and DESCRIBE SEMANTIC VIEW | VERIFIED | sqllogictest Tests 1-4 query `list_semantic_views()` and `describe_semantic_view()` after each mutation |

### Plan 45-02 Must-Have Truths

| # | Truth | Status | Evidence |
|---|-------|--------|----------|
| 6 | GET_DDL('SEMANTIC_VIEW', 'name') returns a valid CREATE OR REPLACE SEMANTIC VIEW statement | VERIFIED | render_ddl.rs:186 emits header; all clause emit functions populated; phase45_get_ddl.test Cases 1-8 pass |
| 7 | GET_DDL output includes all clauses: TABLES, RELATIONSHIPS, FACTS, DIMENSIONS, METRICS (when present) | VERIFIED | render_create_ddl conditionally emits RELATIONSHIPS, FACTS, DIMENSIONS, METRICS; sqllogictest Cases 3, 4, 5 verify each |
| 8 | GET_DDL output includes metadata annotations: COMMENT, WITH SYNONYMS, PRIVATE | VERIFIED | `emit_comment` and `emit_synonyms` called on tables/dims/metrics/facts; sqllogictest Case 2 verifies all three |
| 9 | GET_DDL output round-trips: executing the output DDL produces an equivalent definition | VERIFIED | sqllogictest Case 6 full round-trip; Case 9 comment-with-quotes round-trip |

**Score:** 9/9 must-have truths verified

### Required Artifacts

| Artifact | Expected | Status | Details |
|----------|----------|--------|---------|
| `src/parse.rs` | DdlKind::Alter/AlterIfExists with SET/UNSET COMMENT dispatch | VERIFIED | Variants renamed; `rewrite_alter` and `validate_alter` helpers route sub-operations; 13 new unit tests for alter rewrite |
| `src/ddl/alter.rs` | AlterSetCommentVTab and AlterUnsetCommentVTab with catalog read-modify-write | VERIFIED | `AlterCommentState`, `AlterSetCommentVTab`, `AlterUnsetCommentVTab`, `persist_comment_update`, `alter_comment_impl` all present |
| `src/lib.rs` | Registration of 4 new table functions for SET/UNSET COMMENT | VERIFIED | All 4 registered: `alter_semantic_view_set_comment`, `alter_semantic_view_set_comment_if_exists`, `alter_semantic_view_unset_comment`, `alter_semantic_view_unset_comment_if_exists` |
| `test/sql/phase45_alter_comment.test` | sqllogictest integration tests | VERIFIED | 161 lines, 23 statement/query directives, 10 distinct test scenarios |
| `test/sql/TEST_LIST` | Updated list including both phase45 tests | VERIFIED | Both `phase45_alter_comment.test` and `phase45_get_ddl.test` present |
| `src/render_ddl.rs` | render_create_ddl + helpers (plan deviation: moved from get_ddl.rs) | VERIFIED | 517 lines; `render_create_ddl`, `escape_single_quote`, `emit_comment`, `emit_synonyms`, all clause emitters present; 21 unit tests |
| `src/ddl/get_ddl.rs` | GetDdlScalar VScalar implementation | VERIFIED | 69 lines; `GetDdlScalar`, `impl VScalar for GetDdlScalar`, SEMANTIC_VIEW case-insensitive check, `render_create_ddl` call |
| `src/ddl/mod.rs` | Module declaration for get_ddl | VERIFIED | `pub mod get_ddl;` present |
| `test/sql/phase45_get_ddl.test` | sqllogictest integration tests for GET_DDL | VERIFIED | 423 lines, 59 statement/query directives, 10 cases including round-trip |

### Key Link Verification

| From | To | Via | Status | Details |
|------|----|-----|--------|---------|
| `src/parse.rs` | `src/ddl/alter.rs` | DDL rewrite to `alter_semantic_view_set_comment` table function call | WIRED | `rewrite_alter` produces `SELECT * FROM alter_semantic_view_set_comment(...)` |
| `src/ddl/alter.rs` | `src/catalog.rs` | `catalog_upsert` for in-memory update | WIRED | `catalog_upsert(&state.catalog, name, &new_json)` at alter.rs:246 |
| `src/lib.rs` | `src/ddl/alter.rs` | `register_table_function_with_extra_info` with `AlterSetCommentVTab` | WIRED | All 4 VTabs registered; imports include `AlterSetCommentVTab`, `AlterUnsetCommentVTab`, `AlterCommentState` |
| `src/ddl/get_ddl.rs` | `src/catalog.rs` (via render_ddl.rs) | `state.read()` CatalogState read for JSON lookup | WIRED | `let guard = state.read().unwrap(); guard.get(&name)` at get_ddl.rs:30 |
| `src/ddl/get_ddl.rs` | `src/render_ddl.rs` | `render_create_ddl` call within VScalar invoke | WIRED | `use crate::render_ddl::render_create_ddl` at get_ddl.rs:15; called at get_ddl.rs:52 |
| `src/lib.rs` | `src/ddl/get_ddl.rs` | `register_scalar_function_with_state::<GetDdlScalar>` | WIRED | `con.register_scalar_function_with_state::<GetDdlScalar>("get_ddl", &catalog_state)` at lib.rs:552 |

### Data-Flow Trace (Level 4)

| Artifact | Data Variable | Source | Produces Real Data | Status |
|----------|---------------|--------|--------------------|--------|
| `AlterSetCommentVTab` | catalog JSON | `state.catalog.read()` then `catalog_upsert` | Yes — reads existing stored JSON, mutates it, writes back to in-memory map and DB | FLOWING |
| `AlterUnsetCommentVTab` | catalog JSON | Same as above, sets `comment = None` | Yes | FLOWING |
| `GetDdlScalar` | DDL string | `state.read().unwrap().get(&name)` -> `serde_json::from_str` -> `render_create_ddl` | Yes — reads live catalog JSON, deserializes full SemanticViewDefinition, reconstructs DDL | FLOWING |

### Behavioral Spot-Checks

| Behavior | Command | Result | Status |
|----------|---------|--------|--------|
| All Rust unit tests pass | `cargo test` | 36 + 42 + 5 + 1 = 84 tests, 0 failed | PASS |
| All sqllogictest integration tests pass | `just build && just test-sql` | 26 tests run, 0 failed; phase45_alter_comment.test and phase45_get_ddl.test both SUCCESS | PASS |
| DuckLake CI integration tests pass | `just test-ducklake-ci` | 6 passed, 0 failed | PASS |

### Requirements Coverage

| Requirement | Source Plan | Description | Status | Evidence |
|-------------|------------|-------------|--------|----------|
| ALT-01 | 45-01 | User can ALTER SEMANTIC VIEW ... SET COMMENT = '...' | SATISFIED | `AlterSetCommentVTab` implements full DDL path; sqllogictest Tests 1-4 verify end-to-end; REQUIREMENTS.md marked [x] |
| ALT-02 | 45-01 | User can ALTER SEMANTIC VIEW ... UNSET COMMENT | SATISFIED | `AlterUnsetCommentVTab` with `def.comment = None`; sqllogictest Test 3 verifies NULL; REQUIREMENTS.md marked [x] |
| SHOW-07 | 45-02 | GET_DDL('SEMANTIC_VIEW', 'name') returns re-executable CREATE OR REPLACE statement | SATISFIED | `GetDdlScalar` VScalar registered; `render_create_ddl` produces valid DDL; 59 sqllogictest directives verify output; REQUIREMENTS.md checkbox not yet ticked (documentation gap only) |
| SHOW-08 | 45-02 | GET_DDL output round-trips correctly | SATISFIED | phase45_get_ddl.test Case 6 proves round-trip equality; REQUIREMENTS.md checkbox not yet ticked (documentation gap only) |

**Note:** SHOW-07 and SHOW-08 are still marked `[ ]` (pending) in REQUIREMENTS.md despite being implemented and tested. This is a documentation tracking gap that should be corrected in REQUIREMENTS.md — both checkboxes should be `[x]`.

### Anti-Patterns Found

| File | Line | Pattern | Severity | Impact |
|------|------|---------|----------|--------|
| None found | — | No TODO/FIXME/placeholder/stub patterns detected in modified files | — | — |

### Human Verification Required

None. All success criteria are verifiable programmatically. The test suite covers end-to-end behavior including SHOW/DESCRIBE visibility of comment changes and GET_DDL round-trip correctness.

### Gaps Summary

No gaps. All 4 roadmap success criteria and all 9 plan-level must-have truths are verified. The full quality gate (`cargo test`, `just test-sql`, `just test-ducklake-ci`) passes with 0 failures.

The only notable finding is a minor documentation discrepancy: SHOW-07 and SHOW-08 checkboxes in REQUIREMENTS.md are still `[ ]` rather than `[x]`. The implementations are complete and tested — this is purely a tracking document update that was not performed.

---

_Verified: 2026-04-11T22:10:50Z_
_Verifier: Claude (gsd-verifier)_
