> ## Documentation Index
> Fetch the complete documentation index at: https://docs.cube.dev/llms.txt
> Use this file to discover all available pages before exploring further.

# Caching Overview

> Learn how Cube's caching layer accelerates queries with pre-aggregations.

Caching

Cube provides a powerful caching layer through **pre-aggregations** — materialized rollup tables that dramatically accelerate query performance and reduce data warehouse costs.

## How it works

<Steps>
  <Step title="Define pre-aggregations">
    Specify rollup tables in your data model with the measures and dimensions to cache.
  </Step>

  <Step title="Cube builds the cache">
    Cube queries your data warehouse and stores results in Cube Store, a purpose-built caching engine.
  </Step>

  <Step title="Queries are served from cache">
    When a query matches a pre-aggregation, Cube serves it from the cache instead of hitting the warehouse.
  </Step>

  <Step title="Automatic refresh">
    Pre-aggregations are refreshed on a configurable schedule to keep data fresh.
  </Step>
</Steps>

## Defining pre-aggregations

Add pre-aggregations to your cube definitions:

```yaml theme={"dark"}
cubes:
  - name: orders
    # ... measures and dimensions ...

    pre_aggregations:
      - name: orders_by_day
        measures:
          - count
          - total_amount
        dimensions:
          - status
        time_dimension: created_at
        granularity: day
```

## Refresh strategy

Control how often pre-aggregations are rebuilt:

```yaml theme={"dark"}
pre_aggregations:
  - name: orders_by_day
    measures:
      - count
    time_dimension: created_at
    granularity: day
    refresh_key:
      every: "1 hour"
```

<Warning>
  Setting very frequent refresh intervals can increase your data warehouse costs. Balance freshness with cost.
</Warning>

## Benefits

* **10-100x faster queries** compared to hitting the warehouse directly
* **Reduced warehouse costs** by minimizing direct queries
* **Consistent performance** regardless of data volume
* **Automatic query routing** — no changes needed in your application code