Mappings in Elasticsearch

Mappings define how fields are stored and analyzed.

Dynamic Mapping Example

{
  "mappings": {
    "dynamic": true
  }
}

New fields are auto-created.

Explicit Mapping Example

{
  "mappings": {
    "properties": {
      "status": { "type": "keyword" },
      "price": { "type": "float" }
    }
  }
}

Manual control over field types.

Pitfalls

• Dynamic fields bloat index
• Wrong field types (string → text instead of keyword)
• Hard to fix later without reindexing

Best Practice: Always use explicit mappings for important fields.