Boolean and binary types in Elasticsearch

Introduction

Boolean and binary types help store simple true/false values and raw data in Elasticsearch. They make searching and filtering data easier and faster.

When you want to store yes/no or true/false answers, like if a user is active or not.

When you need to save small files or images as raw data inside Elasticsearch.

When filtering search results based on true/false conditions, like showing only verified users.

When you want to store flags or switches that control features in your data.

When you want to store encoded data that is not text, like encrypted information.

Syntax

Elasticsearch

PUT /my_index
{
  "mappings": {
    "properties": {
      "is_active": { "type": "boolean" },
      "file_data": { "type": "binary" }
    }
  }
}

The boolean type stores true or false values.

The binary type stores base64 encoded data, like files or images.

Examples

This example creates a field email_verified that stores true or false values.

Elasticsearch

PUT /users
{
  "mappings": {
    "properties": {
      "email_verified": { "type": "boolean" }
    }
  }
}

This example creates a field attachment to store raw file data encoded in base64.

Elasticsearch

PUT /documents
{
  "mappings": {
    "properties": {
      "attachment": { "type": "binary" }
    }
  }
}

Sample Program

This program creates an index with boolean and binary fields, adds a document with true and base64 data, then searches for documents where is_published is true.

Elasticsearch

PUT /example_index
{
  "mappings": {
    "properties": {
      "is_published": { "type": "boolean" },
      "image_data": { "type": "binary" }
    }
  }
}

POST /example_index/_doc/1
{
  "is_published": true,
  "image_data": "iVBORw0KGgoAAAANSUhEUgAAAAUA"
}

GET /example_index/_search
{
  "query": {
    "term": { "is_published": true }
  }
}

Important Notes

Boolean fields accept only true or false values, no other types.

Binary fields must be base64 encoded before storing.

Binary data is not searchable but can be retrieved and decoded.

Summary

Boolean type stores true/false values for easy filtering.

Binary type stores raw data encoded in base64, like files or images.

Use these types to organize and search your data efficiently in Elasticsearch.

Practice

1. What type of data does the boolean type in Elasticsearch store?

easy

A. True or false values

B. Text strings

C. Numbers with decimals

D. Base64 encoded files

Solution

1. Step 1: Understand the boolean type purpose

   The boolean type is designed to store values that represent true or false states.

2. Step 2: Compare with other data types

   Text strings, numbers, and base64 encoded files are stored in different types like text, float, or binary, not boolean.

3. Final Answer:

   True or false values -> Option A

4. Quick Check:

   Boolean = true/false [OK]

Hint: Boolean means true or false only [OK]

Common Mistakes:

• Confusing boolean with text or number types
• Thinking boolean stores encoded files
• Assuming boolean can hold multiple values

2. Which of the following is the correct way to define a binary field in an Elasticsearch mapping?

easy

A. {
"my_field": {"type": "text"}
}

B. {
"my_field": {"type": "boolean"}
}

C. {
"my_field": {"type": "binary"}
}

D. {
"my_field": {"type": "integer"}
}

Solution

1. Step 1: Identify the binary type syntax

   In Elasticsearch, a binary field is defined with "type": "binary" inside the mapping.

2. Step 2: Check other options

   Options A, B, and D define other types (text, boolean, integer) which are not binary.

3. Final Answer:

   { "my_field": {"type": "binary"} } -> Option C

4. Quick Check:

   Binary type uses "type": "binary" [OK]

Hint: Binary type always uses "type": "binary" in mapping [OK]

Common Mistakes:

• Using boolean or text instead of binary
• Missing quotes around type name
• Incorrect JSON structure

3. Given this Elasticsearch document mapping and data:

{
  "mappings": {
    "properties": {
      "is_active": {"type": "boolean"},
      "file_data": {"type": "binary"}
    }
  }
}

Document:
{
  "is_active": true,
  "file_data": "SGVsbG8gd29ybGQ="
}

What will be the value of is_active when retrieved?

medium

A. null

B. true

C. false

D. "SGVsbG8gd29ybGQ="

Solution

1. Step 1: Understand the boolean field value

   The field "is_active" is boolean and set to true in the document.

2. Step 2: Confirm retrieval value

   When retrieved, the boolean field returns the stored true value, not the binary data or null.

3. Final Answer:

   true -> Option B

4. Quick Check:

   Boolean field returns true/false as stored [OK]

Hint: Boolean fields return true or false as stored [OK]

Common Mistakes:

• Confusing binary field value with boolean
• Expecting base64 string for boolean field
• Assuming null if not explicitly queried

4. You have this Elasticsearch mapping snippet:

{
  "properties": {
    "flag": {"type": "boolean"},
    "data": {"type": "binary"}
  }
}

Which of the following is a mistake that will cause an error when indexing a document?

medium

A. {"flag": "yes", "data": "dGVzdA=="}

B. {"flag": true, "data": "dGVzdA=="}

C. {"flag": false, "data": ""}

D. {"flag": false, "data": "dGVzdA=="}

Solution

1. Step 1: Check boolean field value types

   The boolean field "flag" must be true or false, not strings like "yes".

2. Step 2: Validate binary field values

   The binary field "data" expects base64 encoded strings, which "dGVzdA==" is valid for.

3. Final Answer:

   {"flag": "yes", "data": "dGVzdA=="} -> Option A

4. Quick Check:

   Boolean must be true/false, not string [OK]

Hint: Boolean fields accept only true or false, not strings [OK]

Common Mistakes:

• Using string 'yes' or 'no' for boolean
• Passing non-base64 strings to binary fields
• Leaving binary field empty without quotes

5. You want to store user profile pictures in Elasticsearch using the binary type and also keep a flag if the user is verified using boolean. Which of the following mapping and document pairs is correct and efficient?

hard

A. {
"mappings": {
"properties": {
"profile_pic": {"type": "text"},
"verified": {"type": "boolean"}
}
}
}

Document:
{
"profile_pic": "iVBORw0KGgoAAAANSUhEUgAAAAUA",
"verified": "yes"
}

B. {
"mappings": {
"properties": {
"profile_pic": {"type": "binary"},
"verified": {"type": "boolean"}
}
}
}

Document:
{
"profile_pic": "not_base64_data",
"verified": true
}

C. {
"mappings": {
"properties": {
"profile_pic": {"type": "binary"},
"verified": {"type": "text"}
}
}
}

Document:
{
"profile_pic": "iVBORw0KGgoAAAANSUhEUgAAAAUA",
"verified": false
}

D. {
"mappings": {
"properties": {
"profile_pic": {"type": "binary"},
"verified": {"type": "boolean"}
}
}
}

Document:
{
"profile_pic": "iVBORw0KGgoAAAANSUhEUgAAAAUA",
"verified": true
}

Solution

1. Step 1: Check mapping types for fields

   The profile picture should be stored as binary type with base64 data, and verified as boolean true/false.

2. Step 2: Validate document values

   { "mappings": { "properties": { "profile_pic": {"type": "binary"}, "verified": {"type": "boolean"} } } } Document: { "profile_pic": "iVBORw0KGgoAAAANSUhEUgAAAAUA", "verified": true } uses binary type with base64 string and boolean true, which is correct and efficient.

3. Step 3: Identify errors in other options

   { "mappings": { "properties": { "profile_pic": {"type": "text"}, "verified": {"type": "boolean"} } } } Document: { "profile_pic": "iVBORw0KGgoAAAANSUhEUgAAAAUA", "verified": "yes" } uses text for binary and string "yes" for boolean, which is incorrect.
   { "mappings": { "properties": { "profile_pic": {"type": "binary"}, "verified": {"type": "text"} } } } Document: { "profile_pic": "iVBORw0KGgoAAAANSUhEUgAAAAUA", "verified": false } uses text for boolean field.
   { "mappings": { "properties": { "profile_pic": {"type": "binary"}, "verified": {"type": "boolean"} } } } Document: { "profile_pic": "not_base64_data", "verified": true } has invalid base64 data for binary field.

4. Final Answer:

   Mapping and document with binary and boolean types correctly used -> Option D

5. Quick Check:

   Binary = base64, Boolean = true/false [OK]

Hint: Binary needs base64 data; boolean must be true or false [OK]

Common Mistakes:

• Using text type for binary data
• Passing non-base64 strings to binary fields
• Using strings like 'yes' for boolean fields