A range aggregation in Elasticsearch is a way to group documents based on a numeric or date field, and then count the number of documents that fall within a specified range or set of ranges.
When you perform a range aggregation, you specify the name of the field you want to aggregate on, and then define one or more ranges. Each range is defined by a minimum value, a maximum value, and a boolean flag indicating whether the range is inclusive or exclusive. Elasticsearch then groups the documents based on the value of the field, and counts the number of documents that fall within each range.
For example, let’s say you have a set of documents that represent products, and each document has a “price” field that represents the price of the product. You could perform a range aggregation on the “price” field with two ranges: one for products that cost less than $50, and one for products that cost $50 or more. Elasticsearch would then return a histogram with the number of products that fall into each range.
You can also perform range aggregations on date fields, using the same syntax as for numeric fields. This allows you to group documents based on the date or time they were created, modified, or accessed, and to count the number of documents that fall within a specified period of time.
Range aggregations can be useful for a wide range of applications, such as analyzing sales data, monitoring server performance, or tracking user activity. They allow you to quickly and easily group documents into meaningful categories, and to gain insights into patterns and trends in your data.