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title: 'Data Accelerators' sidebar_label: 'Data Accelerators' description: 'Data acceleration engines for local materialization and query acceleration in Spice' image: /img/og/data-accelerators.png sidebar_position: 2 pagination_prev: null pagination_next: null

Data sourced by Data Connectors can be locally materialized and accelerated using a Data Accelerator.

A Data Accelerator queries/fetches data from a connected data source and stores/updates it locally in an embedded acceleration engine, such as Spice Cayenne, DuckDB, or SQLite. To set data refresh behavior, such as refreshing data on an interval, see Data Refresh.

Dataset acceleration is enabled by setting the acceleration configuration:

For the complete reference specification, see datasets.

By default, datasets are locally materialized using in-memory Arrow records.

Supported Data Accelerators

Name	Description	Status	Engine Modes
arrow	In-Memory Arrow Records	Stable	memory
cayenne	Spice Cayenne	Beta	file, file_create, file_update
duckdb	Embedded DuckDB	Stable	memory, file
postgres	Attached PostgreSQL	Release Candidate	N/A
sqlite	Embedded SQLite	Release Candidate	memory, file
turso

Choosing an Accelerator

Select the appropriate accelerator based on dataset size, query patterns, and resource constraints:

Use Case	Recommended Accelerator	Rationale
Small datasets (under 1 GB), maximum speed	arrow	In-memory storage provides lowest latency
Medium datasets (1-100 GB), complex SQL	duckdb	Mature SQL support with memory management
Large datasets (100 GB - 1+ TB), scalable analytics	cayenne	Vortex columnar format scales beyond single-file limits
Point lookups on large datasets	cayenne	Vortex provides 100x faster random access vs Parquet
Simple queries, low resource usage	sqlite	Lightweight, minimal overhead
Async operations, concurrent workloads	turso	Native async support, modern connection pooling
External database integration	postgres	Use existing PostgreSQL infrastructure

Spice Cayenne vs DuckDB

Both Spice Cayenne and DuckDB support file-based acceleration, but differ in architecture and performance characteristics:

Choose Spice Cayenne when:

• Datasets exceed ~1 TB
• Multi-file data ingestion is required (e.g., partitioned S3 data)
• Lower memory overhead is preferred
• Workloads benefit from Vortex's 10-20x faster scans
• Point lookups and random access patterns are common (100x faster than Parquet)

Choose DuckDB when:

• Datasets are under ~1 TB
• Complex SQL features are required (window functions, CTEs)
• Existing DuckDB tooling integration is beneficial
• Explicit index control is required

Data Types

Data Accelerators may not support all possible Apache Arrow data types. For complete compatibility, see specifications.

:::warning[Memory Considerations]

When accelerating a dataset using mode: memory (the default), 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, sqlite, and turso accelerators by specifying mode: file.

:::

Schema Handling

Data accelerators store the schema that Spice infers from the data source at startup. This schema is fixed for the lifetime of the runtime process and defines the column names, data types, and nullability of the accelerated table.

If the source schema changes while the runtime is running (for example, new columns are added or data types change), subsequent data refreshes into the accelerator will fail because the incoming data no longer matches the schema of the accelerated table. Restart the runtime to re-infer the schema and re-initialize the accelerated table.

For details on how schema inference works per connector and recommendations for managing schema drift, see Schema Inference.

Data Accelerator Docs

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Related Documentation

• Performance Tuning - Comprehensive optimization guide
• Managing Memory Usage - Memory configuration reference
• Data Refresh - Refresh mode configuration
• Indexes - Index configuration for DuckDB, SQLite, and Turso