chryso 0.0.2

Chryso is a Calcite-style SQL parser + optimizer engine in Rust.
Documentation 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80

# Chryso

Chryso is a Calcite-style SQL parser + optimizer engine in Rust. It focuses on a clean, modular pipeline (AST -> logical plan -> Cascades optimizer -> physical plan -> adapter) and keeps the core engine execution-agnostic.

## Features
- Multi-dialect SQL parsing (Postgres + MySQL first)
- Cascades optimizer with logical and physical rules
- Cost and statistics hooks via ANALYZE and a lightweight catalog
- Adapter-based execution (DuckDB first, Velox next)

## Status
- Parser, planner, and core Cascades skeleton are implemented
- DuckDB adapter translates physical plans to SQL and executes simple queries/DML
- CI builds and tests with and without the DuckDB feature

## Workspace Layout
```
crates/
  core/       AST, errors, formatting helpers
  parser/     Dialect-aware parser
  planner/    Logical/physical plan definitions + builder
  optimizer/  Cascades skeleton (memo, rules, cost)
  metadata/   Catalog, stats cache, analyze hooks
  adapter/    Execution adapters (DuckDB, mock)
  parser_yacc/ Yacc scaffold (validation)
src/
  lib.rs      Facade crate re-exports
  bin/
    chryso-cli.rs
```

## Quick Start

Run the CLI (mock adapter by default):
```bash
cargo run --bin chryso-cli
```

Run the DuckDB demo:
```bash
cargo run --example duckdb_demo --features duckdb
```

## Tests

All tests:
```bash
cargo test
```

With DuckDB:
```bash
cargo test --features duckdb
```

Plan snapshot tests:
- Inputs: `tests/testdata/plan/case1/in.json`
- Expected outputs: `tests/testdata/plan/case1/out.json`

Record snapshots:
```bash
CHRYSO_RECORD=1 cargo test --test plan_snapshot
```

## Docs
- `docs/ARCHITECTURE.md` for the planning pipeline and module overview
- `docs/RULES.md` for rule conventions and current rule set
- `docs/ADAPTERS.md` for adapter design
- `docs/ROADMAP.md` for milestones and TODOs

## Roadmap (Highlights)
- Parser: expand dialect coverage and AST compatibility
- Logical rewrites: constant folding and predicate simplification
- Cascades: richer rule library and join order enumeration
- Costing: integrate ANALYZE stats into cost models
- Physical planning: enforcers and required properties
- Adapters: stabilize DuckDB, then add Velox

## License
TBD.