# Comparisons

Exograph overlaps with text search, structural search, dependence analysis, and semantic code analysis tools. The key difference is that Exograph is an Elixir-specific DuckDB/QuackDB code fact index that uses ExAST as its final structural verifier.

## Overview

| Tool | Scope | Storage | Query style | Elixir AST-aware? | Best for |
|------|-------|---------|-------------|-------------------|----------|
| `ripgrep` | local text search | none | regex/text | no | fast ad-hoc text search |
| ExAST | structural AST matching | none/advisory terms | AST patterns/selectors | yes | exact search and patching |
| Reach | dependence analysis | in-memory graph/reports | APIs / Mix tasks | yes | call/data/control-flow analysis |
| CodeQL | semantic code analysis | CodeQL database | QL language | not first-class Elixir | security analysis at scale |
| Sourcegraph | cross-repo search | external index | text/structural depending setup | not Elixir-specific | organization-wide search |
| Exograph | Elixir code fact index | DuckDB/QuackDB | ExAST + Ecto-shaped DSL | yes | local/self-hosted Elixir code intelligence; large Hex package indexing |

## Exograph vs ExAST

| Question | ExAST | Exograph |
|----------|-------|----------|
| What is indexed? | Nothing by default; exposes advisory terms | Files, fragments, comments, symbols, references, calls |
| Storage | Source/in-memory | DuckDB/QuackDB |
| Matching authority | ExAST | ExAST |
| Best for | exact AST search, replace, patching, selector semantics | persisted/cross-package code intelligence |
| Scale | scan source or caller-managed index terms | query persisted candidates, then verify with ExAST |

Exograph depends on ExAST. It does not replace it.

## Exograph vs Reach

| Question | Reach | Exograph |
|----------|-------|----------|
| Primary model | dependence graph | normalized code fact index |
| Output | maps, checks, reports, graph queries | persisted rows and query hits |
| Storage | analysis-time graph | DuckDB/QuackDB |
| Role | semantic extractor/analyzer | storage/query layer |
| Relationship | provides call graph facts | persists and queries Reach facts |

Exograph started as infrastructure to run Reach and ExAST against larger codebases and package sets.

## Exograph vs CodeQL

| Question | CodeQL | Exograph |
|----------|--------|----------|
| Languages | many | Elixir-focused |
| Query language | QL | Elixir API / Ecto-shaped DSL / ExAST selectors |
| Database | CodeQL database | DuckDB/QuackDB |
| Semantic model | CodeQL libraries | ExAST + Reach + normalized facts |
| Deployment | CodeQL CLI / GitHub Advanced Security | local/self-hosted Elixir library |
| Scale | organization-wide | public Hex package corpus |

Exograph is CodeQL-style in the sense that it indexes code facts and lets you ask semantic questions over them. It is not a CodeQL-compatible database or QL runtime.

## Exograph vs Sourcegraph

Sourcegraph is an organization-wide code search product. Exograph is a library and schema for Elixir-specific code intelligence. Exograph is useful when you want local/self-hosted indexed facts and AST-verified Elixir queries rather than a general cross-language search UI.

## Scale

Exograph has been dogfooded against the public Hex package corpus with millions of fragments, definitions, references, and call edges. The current production deployment uses sharded DuckDB files managed through QuackDB and queried through `%Exograph.ShardedIndex{}`.