Query Transformation Techniques
Explore methods to rephrase or expand user queries for more effective retrieval from the vector database.
Query Transformation Techniques is a free Vector Databases: Pinecone, Weaviate & pgvector lesson on CoddyKit — lesson 1 of 4. You can read the complete lesson below for free — then practise it hands-on in the browser with a built-in code editor and a 24/7 AI tutor. It is part of the Vector Databases: Pinecone, Weaviate & pgvector learning path, one of 4 lessons in the course, and your progress syncs across the web and the CoddyKit app.
What's Query Transformation?
In Retrieval Augmented Generation (RAG), the quality of the information retrieved from your vector database directly impacts the LLM's response. Sometimes, the raw user query isn't ideal for retrieval.
Query transformation is the process of modifying a user's original query to make it more effective for searching your vector database.
Why Original Queries Fall Short
User queries can be:
- Too short or vague: Lacking enough detail for precise retrieval.
- Ambiguous: Open to multiple interpretations.
- Colloquial: Using informal language that doesn't match document embeddings.
- Complex: Asking multiple questions at once.
These issues lead to irrelevant context being retrieved, impacting RAG quality.
Bridging the Semantic Gap
Your vector database stores information as numerical vectors (embeddings). For effective retrieval, the query's embedding needs to be semantically similar to the embeddings of relevant documents.
Query transformation helps by:
- Adding more context.
- Clarifying intent.
- Aligning query terms with document vocabulary.
This "bridges the semantic gap" for better matches.
Technique 1: Query Expansion
Query expansion involves adding more terms or phrases to the original query. This makes the search broader and increases the chances of hitting relevant documents.
Common methods include:
- Adding synonyms.
- Including related concepts.
- Using domain-specific jargon.
This technique is especially useful for short, vague queries.
Simple Keyword Expansion
Here's a basic Python example where we manually expand a query with related terms. In real systems, an LLM might generate these expansions automatically.
def expand_query_keywords(query):
expansion_map = {
"AI": ["artificial intelligence", "machine learning", "deep learning"],
"vector DB": ["vector database", "embedding store", "Pinecone", "Weaviate"]
}
expanded_terms = []
for keyword, additions in expansion_map.items():
if keyword.lower() in query.lower():
expanded_terms.extend(additions)
return query + " " + " ".join(expanded_terms)
# Example usage
user_query = "What is AI?"
transformed_query = expand_query_keywords(user_query)
print(f"Original: {user_query}")
print(f"Transformed: {transformed_query}")Technique 2: Query Rewriting/Rephrasing
Query rewriting (or rephrasing) uses an LLM to generate a completely new query that is clearer, more specific, or better aligned with the expected content of your documents.
This is particularly effective for:
- Ambiguous questions.
- Conversational queries.
- Queries that implicitly refer to past turns in a conversation.
Rewriting with an LLM
This Python snippet demonstrates how you might use an LLM to rephrase a user query. In a real application, llm_api_call would interact with models like OpenAI GPT or a local LLM.
import os
# Placeholder for an actual LLM API call
def llm_api_call(prompt):
# For demonstration, we'll simulate a response.
if "rephrase" in prompt.lower() and "vector databases" in prompt.lower():
return "Explain the core components and function of vector databases."
return "Could not rephrase query effectively."
def rephrase_query_with_llm(original_query):
prompt = f"Rephrase the following user query to be more effective for searching a technical documentation database about vector databases: '{original_query}'"
rephrased_query = llm_api_call(prompt)
return rephrased_query
# Example usage
user_query = "Tell me about vector DBs."
transformed_query = rephrase_query_with_llm(user_query)
print(f"Original: {user_query}")
print(f"Transformed: {transformed_query}")Technique 3: Sub-Query Generation
When a user asks a complex question that involves multiple aspects, a single query might not retrieve all necessary information. Sub-query generation breaks down a complex query into several simpler, more focused queries.
Each sub-query can then be used to retrieve specific pieces of context, which are then combined for the LLM.
Generating Sub-Queries
Here's a conceptual Python example for generating sub-queries. An LLM is often used to parse the original query and identify distinct questions.
import os
# Placeholder for an actual LLM API call
def llm_api_call_sub_query(prompt):
if "break down" in prompt.lower() and "Pinecone" in prompt.lower():
return ["What is Pinecone?", "How do I upsert data into Pinecone?", "What is a Pinecone index?"]
return ["Could not break down query."]
def generate_sub_queries(original_query):
prompt = f"Break down the following complex user query into a list of simpler, distinct questions for retrieving information from a vector database: '{original_query}'"
sub_queries = llm_api_call_sub_query(prompt)
return sub_queries
# Example usage
user_query = "How do I use Pinecone for storing and querying embeddings?"
transformed_queries = generate_sub_queries(user_query)
print(f"Original: {user_query}")
print(f"Sub-queries: {transformed_queries}")Hybrid & Contextual Transformations
Effective RAG often combines these techniques. You might first rephrase a query, then expand it. Also, consider the conversational context.
- Multi-turn awareness: Use previous turns to enrich the current query.
- Hybrid approaches: Combine transformations with traditional keyword search.
Experimentation is key to finding what works best for your data!
Understanding Query Transformation
Which of the following scenarios would MOST benefit from using query expansion as a transformation technique?
Recap: Transforming Queries
You've learned that query transformation is crucial for improving RAG performance by making user queries more effective for vector database retrieval.
- Query Expansion: Adds terms to broaden search.
- Query Rewriting: Rephrases for clarity and specificity.
- Sub-Query Generation: Breaks down complex queries.
Mastering these techniques will significantly enhance the quality of your RAG applications!
Frequently asked questions
Is the “Query Transformation Techniques” lesson free?
Yes — the full text of “Query Transformation Techniques” is free to read here on the web, and the Vector Databases: Pinecone, Weaviate & pgvector course includes 4 lessons in total. To practise it interactively (a built-in code editor and a 24/7 AI tutor) and unlock the rest of the Vector Databases: Pinecone, Weaviate & pgvector course, upgrade to CoddyKit PRO.
What will I learn in “Query Transformation Techniques”?
Explore methods to rephrase or expand user queries for more effective retrieval from the vector database. You practise Vector Databases: Pinecone, Weaviate & pgvector with hands-on code you run directly in the browser, and a 24/7 AI tutor answers your questions as you work through the lesson.
Do I need any experience to start Vector Databases: Pinecone, Weaviate & pgvector?
No prior experience is required. Vector Databases: Pinecone, Weaviate & pgvector on CoddyKit is structured for beginners through advanced learners; this is — lesson 1 of 4, so you can start here or from the beginning and move at your own pace.
How long does the “Query Transformation Techniques” lesson take?
Most CoddyKit lessons take about 5–10 minutes. Each one is bite-sized and interactive, so you make steady progress and pick up exactly where you left off across the web and the app.
Can I write and run code in this Vector Databases: Pinecone, Weaviate & pgvector lesson?
Yes. Every Vector Databases: Pinecone, Weaviate & pgvector lesson includes a built-in code editor, so you write and run real code right in your browser and get instant AI feedback — no local setup required.
All lessons in this course
- Query Transformation Techniques
- Multi-Stage RAG Pipelines
- Evaluating RAG System Performance
- Reranking Retrieved Results