<!-- nornir:class: reasoning -->
# Releases
> New here? The plain-English version — "how do I build skade on arrow 58, where's
> the perf patch, when do I drop the fork" — is
> [`arrow58-for-dummies.md`](arrow58-for-dummies.md). The forks document
> themselves in `../../iceberg-arrow58/.nornir/README.md` and
> `../../iceberg-datafusion-arrow58/.nornir/README.md`.
## arrow 58 upgrade (2026-06-20) — and the iceberg-datafusion perf patch (INTACT)
skade moved its data plane from arrow **57 → 58** as part of the nordisk
constellation upgrade. Because `iceberg-rust` (and `iceberg-datafusion`) 0.9.1
still pin arrow `^57.1` upstream, the move rides on local `[patch.crates-io]`
forks (stripped by `cargo package/publish`, so the *published* skade is unchanged):
```toml
# skade/skade/Cargo.toml
arrow-array = "58" # was 57
arrow-schema = "58"
arrow-cast = "58"
parquet = "58"
datafusion = "54" # was 52.2 (datafusion 53+ is the first arrow-58 line)
[patch.crates-io]
iceberg = { path = "../../iceberg-arrow58" }
iceberg-datafusion = { path = "../../iceberg-datafusion-arrow58" }
```
![Diagram: skade's Cargo.toml uses [patch.crates-io] to redirect iceberg and iceberg-datafusion to local arrow-58 fork folders; cargo build resolves to the forks and builds clean on arrow 58, while cargo publish strips the patch so published skade still depends on stock iceberg 0.9.1 on arrow 57.](assets/arrow58_patch_fork.svg)
### The perf patch is NOT lost — it moved into the arrow-58 fork
skade's SQL surface (`sql` feature) has long carried a **performance patch** to
`iceberg-datafusion`: a **parallel, per-file partitioned table scan**. Upstream
iceberg-datafusion 0.9.1 exposes the whole table as `UnknownPartitioning(1)` —
a single DataFusion partition, so the scan reads every data file on **one** stream,
serially. The patch instead exposes **one partition per data file**, so
`execute(partition)` reads just that file and DataFusion fans the scan across all
cores (~8× faster on a 32-core box). It's two files: `src/physical_plan/scan.rs`
and `src/table/mod.rs`.
- **Before** (arrow 57): vendored at `skade/bench/vendor/iceberg-datafusion`
(still on disk for reference).
- **Now** (arrow 58): re-applied verbatim into the fork
**`../iceberg-datafusion-arrow58`** (sibling of the skade repo). Verified by
diffing the vendored copy against stock 0.9.1 — upstream has **not** adopted
output partitioning, so the patch is carried as-is. Drop it the moment
iceberg-datafusion ships output partitioning upstream.
### What was a datafusion fix vs. the perf patch (don't conflate them)
Two separate things landed in the arrow-58 fork:
1. **The perf patch** (above) — parallel per-file scan. This is the important,
intentional behaviour change; it is arrow-version-agnostic in spirit but lives
in an arrow-bound crate, so it's pinned to the fork.
2. **datafusion 52 → 54 API-compat fixes** (mechanical, NOT behaviour, NOT arrow):
- `as_any()` was removed from `CatalogProvider`/`SchemaProvider`/`TableProvider`/
`ExecutionPlan`/`PhysicalExpr` (downcast is now provided) — removed every
`fn as_any` override.
- `ExecutionPlan::properties()` now returns `&Arc<PlanProperties>` — each plan's
`plan_properties` field became `Arc<PlanProperties>`, wrapped in `Arc::new`.
- `logical_expr::Cast` field `data_type` → `field: Arc<Field>` — use
`*c.field.data_type()`.
### Scope / isolation
- The patch + datafusion live **only behind skade's `sql` feature**
(`dep:datafusion` + `dep:iceberg-datafusion`). They are **not** in nornir's
release path: nornir depends on `skade` with `default-features = false`, so its
lockfile pulls **zero** datafusion / iceberg-datafusion. The arrow-58 move and
the perf patch are independent concerns from nornir's release gate.
- skade core (writer/reader/catalog) needed **zero** arrow 57→58 source changes —
only the manifest version bumps + the patched forks.