# Implementation Plan: [FEATURE]

**Branch**: `[###-feature-name]` | **Date**: [DATE] | **Spec**: [link]
**Input**: Feature specification from `/specs/[###-feature-name]/spec.md`

**Note**: This template is filled in by the `/speckit.plan` command. See `.specify/templates/plan-template.md` for the execution workflow.

## Summary

[Extract from feature spec: primary requirement + technical approach from research]

## Technical Context

**Language/Version**: Rust 1.85+ 
**Primary Dependencies**: rhai (for scripting backend)
**Testing**: `cargo nextest` via `make test`
**Target Platform**: Embedded Monolithic DB (Linux, macOS, Windows)
**Performance Goals**: Avoid unnecessary heap allocations where possible.
**Constraints**: Ensure strict ACID compliance and avoid `unwrap()`. Use safe Rust standard types (`std::time::Instant` wrapped by Rhai).

## Constitution Check

*GATE: Must pass before Phase 0 research. Re-check after Phase 1 design.*

- [x] **Mainframe Monolith**: Does this maintain the embedded/monolith architecture? (Yes, scripts execute embeddedly).
- [x] **ACID & MVCC**: Does this change respect multi-version concurrency control and strict data integrity? (Yes, time-based commands do not mutate disk state directly outside tx limits).
- [x] **Memory Efficiency**: Does this avoid unnecessary allocations (e.g., `Vec` clones)? (Yes).
- [x] **Safe Rust**: Are errors properly propagated? (Yes).
- [x] **Tests First**: Will this be covered by tests that can be verified via `cargo nextest`? (Yes).

## Project Structure

### Documentation (this feature)

```text
specs/[###-feature]/
├── plan.md              # This file (/speckit.plan command output)
├── research.md          # Phase 0 output (/speckit.plan command)
├── data-model.md        # Phase 1 output (/speckit.plan command)
├── quickstart.md        # Phase 1 output (/speckit.plan command)
├── contracts/           # Phase 1 output (/speckit.plan command)
└── tasks.md             # Phase 2 output (/speckit.tasks command - NOT created by /speckit.plan)
```

### Source Code (repository root)

```text
src/
├── api/           # Public Database API
├── core/          # Core types (Value, Row, Schema, Error)
├── executor/      # Query execution engine
├── functions/     # Built-in functions (scalar, aggregate, window)
├── optimizer/     # Cost-based query optimizer
├── parser/        # SQL parser (lexer, AST, parser)
├── storage/       # Storage engine and MVCC
└── bin/           # CLI binary
tests/             # Integration tests
```

**Structure Decision**: This feature impacts `src/functions/backends/rhai.rs` to add support for mapping `Value::Timestamp` to and from a custom Rhai DateTime object. It also impacts `tests/rhai_scripting_test.rs` to test the new mapping logic.

## Complexity Tracking

> **Fill ONLY if Constitution Check has violations that must be justified**

| Violation | Why Needed | Simpler Alternative Rejected Because |
|-----------|------------|-------------------------------------|
| [e.g., Unsafe Code Used] | [Performance critical loop] | [Safe abstraction was measured to be X% slower in benchmark Y] |
| [e.g., Memory Allocation] | [External library requirement] | [No zero-copy alternatives exist for dependency Z] |
