# Searching data

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This page was generated from content adapted from the [AWS Developer Guide](https://github.com/awsdocs/amazon-opensearch-service-developer-guide.git)
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## Custom packages

* **Tip**\
  Dictionary files use Java heap space proportional to their size. For example, a 2 GiB dictionary file might consume 2 GiB of heap space on a node. If you use large files, ensure that your nodes have enough heap space to accommodate them. [Monitor](https://github.com/kevinslin/aws-reference-notes/blob/main/services/amazon_open_search_service/managedomains-cloudwatchmetrics.md#managedomains-cloudwatchmetrics-cluster-metrics) the `JVMMemoryPressure` metric, and scale your cluster as necessary.
* **Note**\
  If you receive a "package not found" error when you run the script using the AWS CLI, it likely means Boto3 is using whichever Region is specified in \~/.aws/config, which isn't the Region your S3 bucket is in. Either run `aws configure` and specify the correct Region, or explicitly add the Region to the client:

## SQL support

* **Note**\
  If your domain is running Elasticsearch rather than OpenSearch, the format is `_opendistro/_sql`.

## Cross-cluster search

* **Note**\
  If you include remote indexes in the path, you must URL-encode the URI in the domain ARN. For example, use `arn:aws:es:us-east-1:123456789012:domain/my-domain/local_index,dst%3Aremote_index` rather than `arn:aws:es:us-east-1:123456789012:domain/my-domain/local_index,dst:remote_index`.
* **Note**\
  All cross-cluster search requests between domains are encrypted in transit by default as part of node-to-node encryption.

## Learning to Rank

* **Note**\
  To use the Learning to Rank plugin, you must have full admin permissions. To learn more, see [Modifying the master user](https://github.com/kevinslin/aws-reference-notes/blob/main/services/amazon_open_search_service/fgac.md#fgac-forget).
* **Note**\
  You must perform this step outside of OpenSearch Service.
* **Note**\
  You must perform this step outside of OpenSearch Service.
* **Note**\
  You must perform this step outside of OpenSearch Service.

## Asynchronous search

* **Note**\
  If you're using Elasticsearch 7.10 instead of an OpenSearch version, replace `_plugins` with `_opendistro` in all asynchronous search requests.
* **Note**\
  All request parameters that apply to a standard `_search` query are supported. If you're using Elasticsearch 7.10 instead of an OpenSearch version, replace `_plugins` with `_opendistro`.
* **Note**\
  You can monitor asynchronous search statistics in CloudWatch. For a full list of metrics, see [Asynchronous search metrics](https://github.com/kevinslin/aws-reference-notes/blob/main/services/amazon_open_search_service/managedomains-cloudwatchmetrics.md#managedomains-cloudwatchmetrics-asynchronous-search).

## Point in time

* **Note**\
  You can monitor PIT search statistics in CloudWatch. For a full list of metrics, see [Point in time metrics](https://github.com/kevinslin/aws-reference-notes/blob/main/services/amazon_open_search_service/managedomains-cloudwatchmetrics.md#managedomains-cloudwatchmetrics-pit).