opensearch-docs-cn/_ingest-pipelines/processors/remove_by_pattern.md

layout	title	parent	nav_order	redirect_from
default	Remove_by_pattern	Ingest processors	225	/api-reference/ingest-apis/processors/remove_by_pattern/

Remove_by_pattern processor

The remove_by_pattern processor removes the root-level fields from a document by using specified wildcard patterns.

Syntax

The following is the syntax for the remove_by_pattern processor:

{
    "remove_by_pattern": {
        "field_pattern": "field_name_prefix*"
    }
}

{% include copy-curl.html %}

Configuration parameters

The following table lists the required and optional parameters for the remove_by_pattern processor.

Parameter	Required/Optional	Description
field_pattern	Optional	Removes fields that match the specified pattern. All of the metadata fields, such as _index, _version, _version_type, and _id, are ignored if they match the pattern. This option only supports the root-level fields in the document.
exclude_field_pattern	Optional	Removes fields that do not match the specified pattern. All of the metadata fields, such as _index, _version, _version_type, and _id, are ignored if they do not match the pattern. This option only supports the root-level fields in the document. The field_pattern and exclude_field_pattern options are mutually exclusive.
description	Optional	A brief description of the processor.
if	Optional	A condition for running the processor.
ignore_failure	Optional	Specifies whether the processor continues execution even if it encounters errors. If set to true, the failure is ignored. Default is false.
on_failure	Optional	A list of processors to run if the processor fails.
tag	Optional	An identifier tag for the processor. Useful for debugging in order to distinguish between processors of the same type.

Using the processor

Follow these steps to use the processor in a pipeline.

Step 1: Create a pipeline

The following query creates a pipeline named remove_fields_by_pattern that removes the fields that match the pattern foo*:

PUT /_ingest/pipeline/remove_fields_by_pattern
{
  "description": "Pipeline that removes the fields by patterns.",
  "processors": [
    {
      "remove_by_pattern": {
        "field_pattern": "foo*"
      }
    }
  ]
}

{% include copy-curl.html %}

Step 2 (Optional): Test the pipeline

It is recommended that you test your pipeline before you ingest documents. {: .tip}

To test the pipeline, run the following query:

POST _ingest/pipeline/remove_fields_by_pattern/_simulate
{
  "docs": [
    {
      "_index": "testindex1",
      "_id": "1",
      "_source":{
         "foo1": "foo1",
         "foo2": "foo2",
         "bar": "bar"
      }
    }
  ]
}

{% include copy-curl.html %}

Response

The following example response confirms that the pipeline is working as expected:

{
  "docs": [
    {
      "doc": {
        "_index": "testindex1",
        "_id": "1",
        "_source": {
          "bar": "bar"
        },
        "_ingest": {
          "timestamp": "2023-08-24T18:02:13.218986756Z"
        }
      }
    }
  ]
}

Step 3: Ingest a document

The following query ingests a document into an index named testindex1:

PUT testindex1/_doc/1?pipeline=remove_fields_by_pattern
{
  "foo1": "foo1",
  "foo2": "foo2",
  "bar": "bar"
}

{% include copy-curl.html %}

Step 4 (Optional): Retrieve the document

To retrieve the document, run the following query:

GET testindex1/_doc/1

{% include copy-curl.html %}