Add Arrow Data Accelerator documentation (#443)

* Add Arrow Data Accelerator documentation

Fixes #223

Add documentation for the In-Memory Arrow Data Accelerator.

spiceaidocs/docs/components/data-accelerators/arrow.md

@@ -0,0 +1,33 @@
+---
+title: 'In-Memory Arrow Data Accelerator'
+sidebar_label: 'In-Memory Arrow Data Accelerator'
+description: 'In-Memory Arrow Data Accelerator Documentation'
+sidebar_position: 1
+---
+
+The In-Memory Arrow Data Accelerator is the default data accelerator in Spice. It uses Apache Arrow to store data in-memory for fast access and query performance.
+
+## Configuration
+
+To use the In-Memory Arrow Data Accelerator, specify `arrow` as the `engine` for acceleration.
+
+```yaml
+datasets:
+  - from: spice.ai:path.to.my_dataset
+    name: my_dataset
+    acceleration:
+      engine: arrow
+```
+
+## Limitations
+
+- The In-Memory Arrow Data Accelerator does not support persistent storage. Data is stored in-memory and will be lost when the Spice runtime is stopped.
+- The In-Memory Arrow Data Accelerator does not support `Decimal256` (76 digits), as it exceeds Arrow's maximum Decimal width of 38 digits.
+
+:::warning[Memory Considerations]
+
+When accelerating a dataset using the In-Memory Arrow Data Accelerator, some or all of the dataset is loaded into memory. Ensure sufficient memory is available, including overhead for queries and the runtime, especially with concurrent queries.
+
+In-memory limitations can be mitigated by storing acceleration data on disk, which is supported by [`duckdb`](./duckdb.md) and [`sqlite`](./sqlite.md) accelerators by specifying `mode: file`.
+
+:::

spiceaidocs/docs/components/data-accelerators/index.md

@@ -30,10 +30,10 @@ Supported Data Accelerators include:
 
 | Engine Name                       | Description             | Status | Engine Modes     |
 | --------------------------------- | ----------------------- | ------ | ---------------- |
-| `arrow`                           | In-Memory Arrow Records | Alpha  | `memory`         |
-| [`duckdb`](./duckdb.md)           | Embedded DuckDB         | Alpha  | `memory`, `file` |
-| [`sqlite`](./sqlite.md)           | Embedded SQLite         | Alpha  | `memory`, `file` |
-| [`postgres`](./postgres/index.md) | Attached PostgreSQL     | Alpha  |                  |
+| [`arrow`](./arrow.md)             | In-Memory Arrow Records | Beta  | `memory`         |
+| [`duckdb`](./duckdb.md)           | Embedded DuckDB         | Beta  | `memory`, `file` |
+| [`sqlite`](./sqlite.md)           | Embedded SQLite         | Beta  | `memory`, `file` |
+| [`postgres`](./postgres/index.md) | Attached PostgreSQL     | Beta  |                  |
 
 ## Data Types