omnigraph/docs/dev/index.md
aaltshuler 8393fd7946 docs: add datafusion-future-improvements.md to dev docs
Captures the post-PR #111 (Lance 4→6) + PR #113 (structured Expr
pushdown) DataFusion state in one place, so future maintainers don't
have to re-derive what's done, what's free, and what's still on the
table from chat history.

Structure:
- Direct touchpoints (only 2 — narrow surface)
- Shipped: PR-by-PR delta of what's landed
- Passive wins active on DF 53 (PR-linked, with where-it-bites-us
  notes)
- Still on the table, ranked by tier:
  - T1: structural, unblocked today (hydrate_nodes Expr pushdown)
  - T2: gated on Lance v7 (delete Expr via MR-A / issue #112)
  - T3: future-shape unlocks (extension planner, expression
    placement, etc.)
  - T4: won't reach us without major changes (custom ExecutionPlan
    territory)
- Upstream cadence note (Lance dictates the DF version)
- Maintenance section

Linked from docs/dev/index.md so the check-agents-md CI guard
passes.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
2026-05-23 12:52:21 +01:00

3 KiB

Developer Docs

Audience: contributors, maintainers, and coding agents

This is the contributor-facing entry point. These docs explain architecture, invariants, implementation contracts, test ownership, and upstream Lance constraints. User-facing behavior should still be documented through docs/user/index.md and the relevant public reference docs.

Required For Every Non-Trivial Change

Need Read
Architectural rules, known gaps, deny-list invariants.md
Upstream Lance source-of-truth index lance.md
Existing test coverage and test placement testing.md

Architecture And Storage

Area Read
System structure, L1/L2 framing, component diagrams architecture.md
On-disk layout, manifest schema, URI behavior storage.md
Direct-publish writes, D2, staged writes, recovery sidecars runs.md
Query execution, mutation execution, loader flow execution.md
DataFusion: current state, passive wins, future improvements datafusion-future-improvements.md
Index lifecycle and graph topology indexes indexes.md
Branch and commit internals branches-commits.md
Three-way merge implementation and conflicts merge.md
Diff/change-feed implementation changes.md
Branch protection policy branch-protection.md
CODEOWNERS source of truth codeowners.md

Language, Runtime, And Boundaries

Area Read
Schema grammar, catalog, migration planner schema-language.md
Query grammar, IR, lints, mutation restrictions query-language.md
Embedding client and @embed integration embeddings.md
Cedar policy surface and server gating policy.md
Server auth, OpenAPI, endpoint handlers server.md
Error taxonomy and serialization errors.md
Constants and tunables constants.md
Transaction model public contract transactions.md

Project Operations

Area Read
CI and release workflows ci.md
Install and deployment packaging install.md, deployment.md
Release history releases/

Active Implementation Plans

Working documents for in-flight feature work. Removed when the work lands.

Area Read
Schema-lint chassis v1 (MR-694) — --allow-data-loss, soft/hard drops schema-lint-v1-plan.md

Boundary

Developer docs may mention implementation details, stale gaps, upstream Lance blockers, and review rules. User docs should not require that context unless the detail changes the public contract.