Sort processor
The sort
processor sorts an array of items in either ascending or descending order. Numeric arrays are sorted numerically, while string or mixed arrays (strings and numbers) are sorted lexicographically. The processor throws an error if the input is not an array.
The following is the syntax for the sort
processor:
{
"description": "Sort an array of items",
"processors": [
{
"sort": {
"field": "my_array_field",
"order": "desc"
}
}
]
}
Configuration parameters
The following table lists the required and optional parameters for the sort
processor.
Parameter | Required/Optional | Description |
---|---|---|
field | Required | The field to be sorted. Must be an array. |
order | Optional | The sort order to apply. Accepts asc for ascending or desc for descending. Default is asc . |
target_field | Optional | The name of the field in which the sorted array is stored. If not specified, then the sorted array is stored in the same field as the original array (the field variable). |
description | Optional | A description of the processor’s purpose or configuration. |
if | Optional | Specifies to conditionally execute the processor. |
ignore_failure | Optional | Specifies to ignore processor failures. See Handling pipeline failures. |
on_failure | Optional | Specifies a list of processors to run if the processor fails during execution. These processors are executed in the order they are specified. |
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 sort-pipeline
that uses the sort
processor to sort the my_field
in descending order and store the sorted values in the sorted_field
:
PUT _ingest/pipeline/sort-pipeline
{
"description": "Sort an array of items in descending order",
"processors": [
{
"sort": {
"field": "my_array_field",
"order": "desc",
"target_field": "sorted_array"
}
}
]
}
Step 2 (Optional): Test the pipeline
It is recommended that you test your pipeline before you ingest documents.
To test the pipeline, run the following query:
POST _ingest/pipeline/sort-pipeline/_simulate
{
"docs": [
{
"_source": {
"my_array_field": [3, 1, 4, 1, 5, 9, 2, 6, 5]
}
}
]
}
Response
The following example response confirms that the pipeline is working as expected:
{
"docs": [
{
"doc": {
"_index": "_index",
"_id": "_id",
"_source": {
"sorted_array": [
9,
6,
5,
5,
4,
3,
2,
1,
1
],
"my_array_field": [
3,
1,
4,
1,
5,
9,
2,
6,
5
]
},
"_ingest": {
"timestamp": "2024-05-30T22:10:13.405692128Z"
}
}
}
]
}
Step 3: Ingest a document
The following query ingests a document into an index named testindex1
:
POST testindex1/_doc?pipeline=sort-pipeline
{
"my_array_field": [3, 1, 4, 1, 5, 9, 2, 6, 5]
}
Response
The request indexes the document into the index testindex1
and then indexes all documents with the my_array_field
sorted in descending order, as shown in the following response:
{
"_index": "testindex1",
"_id": "no-Py48BwFahnwl9KZzf",
"_version": 1,
"result": "created",
"_shards": {
"total": 2,
"successful": 1,
"failed": 0
},
"_seq_no": 9,
"_primary_term": 2
}
Step 4 (Optional): Retrieve the document
To retrieve the document, run the following query:
GET testindex1/_doc/no-Py48BwFahnwl9KZzf