Range query in Elasticsearch - Step-by-Step Execution

Concept Flow - Range query

Start Range Query

↓

Specify Field

↓

Set Range Conditions

↓

gte

↓

Execute Query

↓

Return Matching Documents

↓

End

The range query starts by choosing a field, then sets conditions like greater than or less than, executes the query, and returns matching documents.

Execution Sample

Elasticsearch

{
  "query": {
    "range": {
      "age": { "gte": 30, "lt": 40 }
    }
  }
}

This query finds documents where the 'age' field is greater than or equal to 30 and less than 40.

Execution Table

Step	Action	Field	Condition	Evaluation	Result
1	Start query	-	-	-	Ready to build range query
2	Specify field	age	-	-	Field set to 'age'
3	Set condition gte	age	gte: 30	Check if age >= 30	Condition added
4	Set condition lt	age	lt: 40	Check if age < 40	Condition added
5	Execute query	age	gte:30 and lt:40	Filter documents by conditions	Documents filtered
6	Return results	-	-	-	Documents with 30 <= age < 40 returned
7	End	-	-	-	Query complete

💡 All conditions applied and matching documents returned

Variable Tracker

Variable	Start	After Step 2	After Step 3	After Step 4	Final
field	undefined	age	age	age	age
conditions	empty	empty	{"gte":30}	{"gte":30, "lt":40}	{"gte":30, "lt":40}
result	none	none	none	none	documents with age >=30 and <40

Key Moments - 2 Insights

Why do we specify both 'gte' and 'lt' instead of just one?

Using both 'gte' and 'lt' defines a range between two values. The execution_table rows 3 and 4 show adding each condition separately to narrow down the results.

What happens if we only use 'gte' without 'lt'?

The query will return all documents with the field value greater than or equal to the specified number, without an upper limit. This is shown by the condition in row 3 alone.

Visual Quiz - 3 Questions

Look at the execution_table, what is the field set to after step 2?

A gte

B age

C undefined

D lt

💡 Hint

Check the 'Field' column in row with Step 2

At which step are both range conditions applied together?

A Step 5

B Step 3

C Step 4

D Step 6

💡 Hint

Look at the 'Condition' and 'Evaluation' columns in the execution_table rows

If we remove the 'lt' condition, how does the 'conditions' variable change after step 4?

A {}

B {"lt":40}

C {"gte":30}

D {"gte":30, "lt":40}

💡 Hint

Refer to variable_tracker 'conditions' row after Step 4

Concept Snapshot

Range query syntax:
{
  "query": {
    "range": {
      "field": { "gte": value1, "lt": value2 }
    }
  }
}
Use 'gte' for greater or equal, 'lt' for less than.
Combines conditions to filter documents within a range.

Full Transcript

The range query in Elasticsearch filters documents by checking if a field's value falls within specified limits. First, you choose the field to check. Then you add conditions like 'gte' (greater than or equal) and 'lt' (less than) to define the range. The query runs and returns documents matching these conditions. For example, setting 'age' with 'gte' 30 and 'lt' 40 returns documents where age is between 30 and 39. The execution table shows each step: starting the query, setting the field, adding conditions, executing, and returning results. Variables track the field name, conditions, and final results. Beginners often wonder why both 'gte' and 'lt' are needed; using both narrows the range precisely. If only 'gte' is used, results have no upper limit. The visual quiz checks understanding of these steps and variable changes.