Saved searches and filters in Elasticsearch - Mini Project: Build & Apply

Saved searches and filters

📖 Scenario: You work at a company that stores product data in Elasticsearch. You want to save common searches and filters to quickly find products later.

🎯 Goal: Build saved search queries with filters in Elasticsearch JSON format.

📋 What You'll Learn

Create an Elasticsearch query with a match_all base

Add a filter for products with price less than 100

Save the filter as a named filter called 'cheap_products'

Print the final saved search JSON

💡 Why This Matters

🌍 Real World

Saved searches and filters help users quickly find relevant data without rewriting queries every time.

💼 Career

Elasticsearch developers and data engineers often create and manage saved searches and filters for efficient data retrieval.

1

Create the base query

Create a variable called saved_search and set it to an Elasticsearch query JSON with a query key containing {"match_all": {}}.

Elasticsearch

# Create a variable called saved_search with a match_all query
# Your code here

Hint

Use a dictionary with keys 'query' and inside it 'match_all' with an empty object.

2

Add a price filter

Add a post_filter key at the top level of saved_search with a range filter on price less than 100. Use the exact structure: {"range": {"price": {"lt": 100}}}.

Elasticsearch

saved_search = {
    "query": {
        "match_all": {}
    }
}
# Add a post_filter for price less than 100 at the top level
# Your code here

Hint

Use the post_filter key at the top level with the range filter inside.

3

Save the filter as a named filter

Wrap the filter inside a bool query with a filter list containing the range filter. Name the filter cheap_products by adding "_name": "cheap_products" inside the range filter. Update saved_search["query"] to this new bool query.

Elasticsearch

saved_search = {
    "query": {
        "match_all": {}
    },
    "post_filter": {
        "range": {
            "price": {
                "lt": 100
            }
        }
    }
}
# Update saved_search["query"] to a bool filter with named filter 'cheap_products'
# Your code here

Hint

Use a bool query with a filter list and add the _name key inside the range filter.

4

Print the saved search JSON

Print the saved_search variable to display the final saved search JSON.

Elasticsearch

saved_search = {
    "query": {
        "bool": {
            "filter": [
                {
                    "range": {
                        "price": {
                            "lt": 100,
                            "_name": "cheap_products"
                        }
                    }
                }
            ]
        }
    },
    "post_filter": {
        "range": {
            "price": {
                "lt": 100
            }
        }
    }
}
# Print the saved_search variable
# Your code here

Hint

Use print(saved_search) to show the JSON.

Practice

1. What is the main purpose of a saved search in Elasticsearch?

easy

A. To create visual charts from data

B. To store raw data permanently

C. To reuse a query easily without rewriting it every time

D. To delete old data automatically

Solution

1. Step 1: Understand what saved searches do

   Saved searches store queries so you can run them again without rewriting.

2. Step 2: Compare options to this purpose

   Only To reuse a query easily without rewriting it every time describes reusing queries easily, which matches saved searches.

3. Final Answer:

   To reuse a query easily without rewriting it every time -> Option C

4. Quick Check:

   Saved searches = reuse queries [OK]

Hint: Saved searches store queries for reuse, not data or visuals [OK]

Common Mistakes:

• Confusing saved searches with data storage
• Thinking saved searches create charts
• Assuming saved searches delete data

2. Which of the following is the correct JSON structure to apply a filter in a saved search?

easy

A. {"query": {"match_all": {}}, "filter": {"term": {"status": "active"}}}

B. {"query": {"filtered": {"filter": {"term": {"status": "active"}}}}}

C. {"query": {"term": {"status": "active"}}}

D. {"filter": {"match": {"status": "active"}}}

Solution

1. Step 1: Recall filter syntax in Elasticsearch saved searches

   Filters are applied inside a filtered query using the "filtered" key.

2. Step 2: Check each option's structure

   {"query": {"filtered": {"filter": {"term": {"status": "active"}}}}} correctly uses "query": {"filtered": {"filter": {...}}} which is the right way to apply filters.

3. Final Answer:

   {"query": {"filtered": {"filter": {"term": {"status": "active"}}}}} -> Option B

4. Quick Check:

   Filter inside filtered query = {"query": {"filtered": {"filter": {"term": {"status": "active"}}}}} [OK]

Hint: Filters go inside a filtered query block in JSON [OK]

Common Mistakes:

• Putting filter outside query block
• Using match instead of term for exact filter
• Missing filtered wrapper for filters

3. Given this saved search JSON snippet, what documents will it return?

{"query": {"filtered": {"query": {"match": {"title": "book"}}, "filter": {"term": {"status": "published"}}}}}

medium

A. Documents with title containing 'book' and status 'published'

B. Documents with title containing 'book' or status 'published'

C. Documents with status 'published' only

D. Documents with title containing 'book' only

Solution

1. Step 1: Analyze the query and filter parts

   The query matches documents where title contains 'book'. The filter restricts to status 'published'.

2. Step 2: Understand filtered query behavior

   Filtered query returns documents matching both query and filter conditions (AND logic).

3. Final Answer:

   Documents with title containing 'book' and status 'published' -> Option A

4. Quick Check:

   Filtered query = query AND filter [OK]

Hint: Filtered queries combine query and filter with AND logic [OK]

Common Mistakes:

• Thinking query and filter use OR logic
• Ignoring the filter part
• Confusing match and term filters

4. You have this saved search JSON:

{"query": {"filtered": {"query": {"match": {"content": "test"}}, "filter": {"term": {"category": "news"}}}}

What is wrong with this JSON?

medium

A. The 'match' query is invalid inside filtered

B. Using 'term' filter instead of 'match'

C. Query should not have a filter

D. Missing closing braces at the end

Solution

1. Step 1: Check JSON structure carefully

   The JSON snippet ends without closing all opened braces, causing syntax error.

2. Step 2: Verify other parts are valid

   Using 'term' filter and 'match' query inside filtered is correct syntax.

3. Final Answer:

   Missing closing braces at the end -> Option D

4. Quick Check:

   JSON must be properly closed [OK]

Hint: Count opening and closing braces to spot JSON errors [OK]

Common Mistakes:

• Ignoring missing braces causing syntax errors
• Thinking 'term' filter is wrong here
• Assuming filters can't be inside queries

5. You want to create a saved search that filters documents where 'status' is 'active' and 'priority' is either 'high' or 'medium'. Which JSON filter correctly represents this?

hard

A. {"query": {"filtered": {"filter": {"bool": {"must": [{"term": {"status": "active"}}, {"terms": {"priority": ["high", "medium"]}]}}}}}}

B. {"query": {"filtered": {"filter": {"term": {"status": "active"}, "terms": {"priority": ["high", "medium"]}}}}}

C. {"query": {"filtered": {"filter": {"or": [{"term": {"status": "active"}}, {"terms": {"priority": ["high", "medium"]}}]}}}}

D. {"query": {"filtered": {"filter": {"must": [{"term": {"status": "active"}}, {"term": {"priority": "high"}}, {"term": {"priority": "medium"}}]}}}}

Solution

1. Step 1: Understand the filter requirements

   Status must be 'active' AND priority must be 'high' OR 'medium'.

2. Step 2: Identify correct bool filter usage

   Use 'must' for AND conditions and 'terms' for multiple values in one field.

3. Step 3: Check each option

   {"query": {"filtered": {"filter": {"bool": {"must": [{"term": {"status": "active"}}, {"terms": {"priority": ["high", "medium"]}]}}}}}} uses 'bool' with 'must' array containing 'term' for status and 'terms' for priority, correctly matching requirements.

4. Final Answer:

   {"query": {"filtered": {"filter": {"bool": {"must": [{"term": {"status": "active"}}, {"terms": {"priority": ["high", "medium"]}]}}}}}} -> Option A

5. Quick Check:

   Bool must + terms array = correct filter [OK]

Hint: Use bool must with terms array for AND + multiple values [OK]

Common Mistakes:

• Using 'or' instead of 'must' for AND logic
• Putting multiple filters without bool wrapper
• Using multiple term filters for same field instead of terms