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

# Choosing between one or more indices

> Learn when to use one index or several indices, depending on your relevance strategy and the user experience you want to create.

export const Records = () => <Tooltip tip="A record is a searchable object in an Algolia index. Each record consists of named attributes." cta="Algolia records" href="/doc/guides/sending-and-managing-data/prepare-your-data#algolia-records">
    records
  </Tooltip>;

Should you create one large index for all your <Records />,
or create multiple indices?
It depends on your ranking strategy and which user experience you want to create.

The number of indices you can create depends on your [plan](https://www.algolia.com/pricing).

## One index or multiple indices for federated search

Federated search describes searching multiple types of data sources.
One data source may be your product catalog.
Another data source may be a support FAQ, or Query Suggestions.

Depending on how you want to organize and present the search results,
you can create one index for all data sources or separate indices for each data source.

To learn more, see [Multi-index search with InstantSearch.js](/doc/guides/building-search-ui/ui-and-ux-patterns/multi-index-search/js).

### Multiple indices for federated search

Using multiple indices is useful when:

* You need to configure each index independently.
  For example, one index for movies, another for actors.
  With federated search, you can show results from both indices in the same interface,
  allowing users to search for both actors and movies.
* You want to **use different ranking strategies** for the same data.
  For example, showing highest-rated and showing most recent movies.

### Single index for federated search

Using a single index is useful when you want to use a **single ranking strategy**.
Users can search for anything, see movies and actors in the same results list,
ranked by the same relevance configuration.

## Multiple indices for Query Suggestions

[Query Suggestions](/doc/guides/building-search-ui/ui-and-ux-patterns/query-suggestions/js) suggest popular search queries to users to help them search faster.
Since Query Suggestions are stored in a separate index, you'd use **multiple indices**:
one for your content, and one for the Query Suggestions.

## Multiple indices for different ranking strategies

Each Algolia index can have one ranking strategy.
If you want to let users switch between different ranking strategies,
for example, to allow sorting by price,
you can use **replica indices**—one index per sorting strategy.

A [replica index](/doc/guides/managing-results/refine-results/sorting/in-depth/replicas) is a copy of the main index with the same records, but a different ranking strategy.

To learn more, see [Create replica indices](/doc/guides/managing-results/refine-results/sorting/how-to/creating-replicas).

## Multiple indices for different environments

If you use different environments, for example, staging and production environments,
it's best to use separate indices for each environment.
This prevents your [Analytics](/doc/guides/search-analytics/overview)
from getting skewed by test queries, prevents indexing accidents, and keeps each environment more secure.

You can use common prefixes to distinguish the different environments, for example, `staging_products` and `prod_products`.
To reduce the number of indexing operations, you can reduce the number of records in your staging environments,
for example, only using 10% of your records.

To learn more, see [Manage your Algolia applications](/doc/guides/sending-and-managing-data/manage-indices-and-apps/manage-your-apps).