---
title: "Query acceleration | Grafana Loki documentation"
description: "Provides instructions on how to write LogQL queries to benefit from query acceleration."
---

# Query acceleration

> Warning
> 
> In Loki and Grafana Enterprise Logs (GEL), Query acceleration using blooms is an [experimental feature](/docs/release-life-cycle/). Engineering and on-call support is not available. No SLA is provided.
> 
> In Grafana Cloud, Query acceleration using Bloom filters is enabled as a [public preview](/docs/release-life-cycle/) for select large-scale customers that are ingesting more that 75TB of logs a month. Limited support and no SLA are provided.

If [bloom filters](/docs/loki/latest/operations/bloom-filters/) are enabled, you can write LogQL queries using [structured metadata](/docs/loki/latest/get-started/labels/structured-metadata/) to benefit from query acceleration.

## Prerequisites

- [Bloom filters](/docs/loki/latest/operations/bloom-filters/) must be enabled. OpenSource and Enterprise customers must [enable bloom filters](/docs/loki/latest/operations/bloom-filters/#enable-bloom-filters). Grafana Support enables Bloom Filters for Cloud Customers who are part of the public preview.
- Logs must be sending [structured metadata](/docs/loki/latest/get-started/labels/structured-metadata/). OpenSource and Enterprise customers must [enable structured metadata](/docs/loki/latest/get-started/labels/structured-metadata/#enable-or-disable-structured-metadata). Structured metadata is enabled by default in Grafana Cloud.

### Query blooms

Queries will be accelerated for any [label filter expression](/docs/loki/latest/query/log_queries/#label-filter-expression) that satisfies *all* of the following criteria:

- The label filter expression using **string equality**, such as `| key="value"`.
  
  - `or` and `and` operators can be used to match multiple values, such as `| detected_level="error" or detected_level="warn"`.
  - *Basic* regular expressions are automatically simplified into a supported expression:
    
    - `| key=~"value"` is converted to `| key="value"`.
    - `| key=~"value1|value2"` is converted to `| key="value1" or key="value2"`.
    - `| key=~".+"` checks for existence of `key`. `.*` is not supported.
- The label filter expression is querying for structured metadata and not a stream label.
- The label filter expression is placed before any [parser expression](/docs/loki/latest/query/log_queries/#parser-expression), [labels format expression](/docs/loki/latest/query/log_queries/#labels-format-expression), [drop labels expression](/docs/loki/latest/query/log_queries/#drop-labels-expression), or [keep labels expression](/docs/loki/latest/query/log_queries/#keep-labels-expression).

To take full advantage of query acceleration with blooms, ensure that filtering structured metadata is done before any parser expression:

In the following example, the query is not accelerated because the structured metadata filter, `detected_level="error"`, is after a parser stage, `json`.

logql ![Copy code to clipboard](/media/images/icons/icon-copy-small-2.svg) Copy

```logql
{cluster="prod"} | logfmt | json | detected_level="error" 
```

In the following example, the query is accelerated because the structured metadata filter is before any parser stage.

logql ![Copy code to clipboard](/media/images/icons/icon-copy-small-2.svg) Copy

```logql
{cluster="prod"} | detected_level="error" | logfmt | json 
```