---
title: Materialized views
source: https://docs.newrelic.com/docs/new-relic-lens/materialized-views
---

For larger, computationally expensive queries, you can store the results as materialized views in Lens. A materialized view stores the precomputed results of a query, allowing you to query the stored data instead of running the complex query each time.

## Benefits of materialized views [#benefits]

Materialized views help you:

-   **Reduce query costs**: Avoid repeatedly fetching the same data from external data sources, which can incur costs based on data scanned or transferred.
-   **Improve performance**: Query precomputed results instead of running complex joins across multiple databases each time, which can reduce load times.
-   **Simplify dashboards**: Store results from multi-database queries and reference them in dashboard widgets.

## Data retention [#retention]

Lens retains materialized views for 1 year from the date of creation or last refresh.

## Pricing [#pricing]

Querying a materialized view incurs a per-GB [data ingest](https://docs.newrelic.com/docs/accounts/accounts-billing/new-relic-one-pricing-billing/data-ingest-billing#data-prices) charge for the data returned.

## Prerequisites [#prerequisites]

Before you start:

-   Verify you have the necessary [permissions](https://docs.newrelic.com/docs/new-relic-lens/set-up-connectors#permissions) to create and manage materialized views.
-   If you need to query external data sources, ensure the [connectors](https://docs.newrelic.com/docs/new-relic-lens/set-up-connectors) are set up.

## Create a materialized view [#create]

To create a materialized view:

1.  Go to **[one.newrelic.com](https://one.newrelic.com) > Administration > Materialized views**.
2.  Click **Create materialized view**.
3.  Enter a unique name for the materialized view.
4.  To query NRDB data, select an account from the account selector. You can join NRDB data from this account with external data sources.
5.  Write your SQL query using the [table reference format](https://docs.newrelic.com/docs/new-relic-lens/query-data#table-format): `connection_name.schema.table`
6.  Click **Create**.

The materialized view appears in the list. Storing results may take some time depending on the complexity of your query.

## Refresh a materialized view [#refresh]

Materialized views contain a snapshot of data from when they were created or last refreshed. To get fresh data:

1.  Go to **[one.newrelic.com](https://one.newrelic.com) > Administration > Materialized views**.
2.  Find the materialized view you want to refresh.
3.  Click the  menu.
4.  Select **Refresh**.

The view runs the original query again and updates the stored results with the latest data.

> #### ⚠️ IMPORTANT
>
> Consider your data freshness requirements when deciding how often to refresh materialized views. Frequently refreshing views with complex queries may increase costs.

## Query a materialized view [#query]

You can query a materialized view like any other table in Lens:

1.  Go to **[one.newrelic.com](https://one.newrelic.com) > Query your data**.

2.  Enable the toggle beside **Notebooks** and click **+ SQL** to add a SQL block.

3.  Reference your materialized view using the `mv.` prefix followed by the view name:

    ```sql
    SELECT * FROM mv.your_materialized_view_name
    ```

4.  Run your query.

You can apply additional filters, joins, or aggregations on the materialized view:

```sql
SELECT store_id, transaction_count
FROM mv.top_stores_mv
WHERE transaction_count > 1000
ORDER BY transaction_count DESC
```

The materialized view acts as a table containing the precomputed results, allowing you to perform further analysis without running the original complex query again.

## Delete a materialized view [#delete]

To delete a materialized view you no longer need:

1.  Go to **[one.newrelic.com](https://one.newrelic.com) > Administration > Materialized views**.
2.  Find the materialized view you want to delete.
3.  Click the  menu.
4.  Select **Delete**.
5.  Confirm the deletion.

> #### ⚠️ CAUTION
>
> Deleting a materialized view is permanent. Any queries or dashboards referencing the deleted view will fail.

For query examples including cross-database joins, refer to [Query materialized views](https://docs.newrelic.com/docs/new-relic-lens/query-data/#query-mv).

## Related topics [#related-topics]

[Lens overview](https://docs.newrelic.com/docs/new-relic-lens/overview)

Learn about Lens features and capabilities.

[Query data with Lens](https://docs.newrelic.com/docs/new-relic-lens/query-data)

Write your first Lens query.

[Set up connectors](https://docs.newrelic.com/docs/new-relic-lens/set-up-connectors)

Connect to external data sources.