How to Use match_all Query in Elasticsearch: Syntax and Examples

Use the match_all query in Elasticsearch to retrieve all documents from an index without filtering. It is a simple query that matches every document and is often used for testing or retrieving full data sets.

Syntax

The match_all query has a simple JSON structure. It contains a query object with match_all as the key. Optionally, you can add a boost value to influence scoring.

• query: The main container for the query.
• match_all: The query type that matches all documents.
• boost (optional): A number to increase or decrease the relevance score.

json

{
  "query": {
    "match_all": {
      "boost": 1.0
    }
  }
}

Example

This example shows how to use the match_all query to retrieve all documents from an Elasticsearch index named products. It returns all documents with their default scores.

json

GET /products/_search
{
  "query": {
    "match_all": {}
  }
}

Output

{
  "hits": {
    "total": {"value": 3, "relation": "eq"},
    "hits": [
      {"_id": "1", "_source": {"name": "Laptop", "price": 1200}},
      {"_id": "2", "_source": {"name": "Phone", "price": 800}},
      {"_id": "3", "_source": {"name": "Tablet", "price": 450}}
    ]
  }
}

Common Pitfalls

One common mistake is to expect match_all to filter or sort documents. It does not filter; it returns everything. Another pitfall is forgetting to wrap match_all inside the query object, which causes syntax errors.

Also, using match_all on very large indexes without pagination can overload your system.

json

{
  "match_all": {}
}

{
  "query": {
    "match_all": {}
  }
}

Quick Reference

Feature	Description
match_all	Matches all documents in the index
boost	Optional score multiplier to influence ranking
Usage	Must be inside a 'query' object
Performance	Use with pagination on large datasets

Key Takeaways

The match_all query returns every document in the index without filtering.

Always place match_all inside the query object to avoid syntax errors.

Use boost to adjust the relevance score if needed.

Avoid retrieving large datasets without pagination to prevent performance issues.

match_all is useful for testing or when you need all documents.