Rerank

serverless: ga
stack: preview 9.2-9.3, ga 9.4.0+

The RERANK command uses an inference model to compute a new relevance score for an initial set of documents, directly within your ES|QL queries.

::::{tab-set}

:::{tab-item} 9.3.0+

Starting in version 9.3.0, RERANK automatically limits processing to 1000 rows by default to prevent accidental high consumption. This limit is applied before the RERANK command executes.

If you need to process more rows, you can adjust the limit using the cluster setting:

PUT _cluster/settings
{
  "persistent": {
    "esql.command.rerank.limit": 5000
  }
}

You can also disable the command entirely if needed:

PUT _cluster/settings
{
  "persistent": {
    "esql.command.rerank.enabled": false
  }
}

:::

:::{tab-item} 9.2.x

No automatic row limit is applied. You should always use LIMIT before or after RERANK to control the number of documents processed, to avoid accidentally reranking large datasets which can result in high latency and increased costs.

For example:

FROM books
| WHERE title:"search query"
| SORT _score DESC
| LIMIT 100  // Limit to top 100 results before reranking
| RERANK "search query" ON title WITH { "inference_id" : "my_rerank_endpoint" }

:::

::::

Syntax

RERANK [column =] query ON field [, field, ...] [WITH { "inference_id" : "my_inference_endpoint" }]

Parameters

column : (Optional) The name of the output column containing the reranked scores. If not specified, the results will be stored in a column named _score. If the specified column already exists, it will be overwritten with the new results.

query : The query text used to rerank the documents. This is typically the same query used in the initial search.

field : One or more fields to use for reranking. These fields should contain the text that the reranking model will evaluate.

my_inference_endpoint : The ID of the inference endpoint to use for the task. The inference endpoint must be configured with the rerank task type.

Description

The RERANK command uses an inference model to compute a new relevance score for an initial set of documents, directly within your ES|QL queries.

Typically, you first use a WHERE clause with a function like MATCH to retrieve an initial set of documents. This set is often sorted by _score and reduced to the top results (for example, 100) using LIMIT. The RERANK command then processes this smaller, refined subset, which is a good balance between performance and accuracy.

When using RERANK with a multivalue column, each value is ranked individually. The score column is then assigned the maximum score resulting from ranking the individual values.

Requirements

To use this command, you must deploy your reranking model in Elasticsearch as an inference endpoint with the task type rerank.

Handling timeouts

RERANK commands may time out when processing large datasets or complex queries. The default timeout is 10 minutes, but you can increase this limit if necessary.

How you increase the timeout depends on your deployment type:

::::{tab-set} :::{tab-item} {{ech}}

• You can adjust {{es}} settings in the Elastic Cloud Console
• You can also adjust the search.default_search_timeout cluster setting using Kibana's Advanced settings :::

:::{tab-item} Self-managed

• You can configure at the cluster level by setting search.default_search_timeout in elasticsearch.yml or updating via Cluster Settings API
• You can also adjust the search:timeout setting using Kibana's Advanced settings
• Alternatively, you can add timeout parameters to individual queries :::

:::{tab-item} {{serverless-full}}

• Requires a manual override from Elastic Support because you cannot modify timeout settings directly ::: ::::

If you don't want to increase the timeout limit, try the following:

• Reduce data volume with LIMIT or more selective filters before the RERANK command
• Split complex operations into multiple simpler queries
• Configure your HTTP client's response timeout (Refer to HTTP client configuration)

Examples

Rerank with a single field

:::{include} ../examples/rerank.csv-spec/simple-query.md :::

Rerank with multiple fields and a custom score column

:::{include} ../examples/rerank.csv-spec/two-queries.md :::

Combine original score with reranked score

:::{include} ../examples/rerank.csv-spec/combine.md :::

Rerank using document snippets

:::{include} ../examples/rerank.csv-spec/rerank-top-snippets.md :::