Build RAG Chatbot with Llamaindex, Pgvector, OpenAI GPT-4o mini, and jina-clip-v1
Introduction to RAG
Retrieval-Augmented Generation (RAG) is a game-changer for GenAI applications, especially in conversational AI. It combines the power of pre-trained large language models (LLMs) like OpenAI’s GPT with external knowledge sources stored in vector databases such as Milvus and Zilliz Cloud, allowing for more accurate, contextually relevant, and up-to-date response generation. A RAG pipeline usually consists of four basic components: a vector database, an embedding model, an LLM, and a framework.
Key Components We'll Use for This RAG Chatbot
This tutorial shows you how to build a simple RAG chatbot in Python using the following components:
- Llamaindex: a data framework that connects large language models (LLMs) with various data sources, enabling efficient retrieval-augmented generation (RAG). It helps structure, index, and query private or external data, optimizing LLM applications for search, chatbots, and analytics.
- Pgvector: an open-source extension for PostgreSQL that enables efficient storage and querying of high-dimensional vector data, essential for machine learning and AI applications. Designed to handle embeddings, it supports fast approximate nearest neighbor (ANN) searches using algorithms like HNSW and IVFFlat. Since it is just a vector search add-on to traditional search rather than a purpose-built vector database, it lacks scalability and availability and many other advanced features required by enterprise-level applications. Therefore, if you prefer a much more scalable solution or hate to manage your own infrastructure, we recommend using Zilliz Cloud, which is a fully managed vector database service built on the open-source Milvus and offers a free tier supporting up to 1 million vectors.)
- OpenAI GPT-4o mini: A streamlined, cost-efficient variant of GPT-4, optimized for scalable AI applications. It balances high performance with reduced computational demands, offering fast response times and lower costs. Ideal for real-time chatbots, content generation, and integration into resource-constrained environments like mobile apps or high-volume transactional systems.
- Jina-CLIP-V1: A multimodal AI model that bridges text and images via shared embeddings, enabling cross-modal retrieval and understanding. Strengths include robust generalization, efficient scalability, and seamless integration for multilingual and visual-text tasks. Ideal for image-text search, content recommendation, and enhancing AI-driven applications in e-commerce, media, and digital asset management.
By the end of this tutorial, you’ll have a functional chatbot capable of answering questions based on a custom knowledge base.
Note: Since we may use proprietary models in our tutorials, make sure you have the required API key beforehand.
Step 1: Install and Set Up Llamaindex
pip install llama-index
Step 2: Install and Set Up OpenAI GPT-4o mini
%pip install llama-index llama-index-llms-openai
from llama_index.llms.openai import OpenAI
llm = OpenAI(
model="gpt-4o-mini",
# api_key="some key", # uses OPENAI_API_KEY env var by default
)
Step 3: Install and Set Up jina-clip-v1
%pip install llama-index-embeddings-jinaai
You may also need other packages that do not come direcly with llama-index.
!pip install Pillow
from llama_index.embeddings.jinaai import JinaEmbedding
embed_model = JinaEmbedding(
api_key=jinaai_api_key,
model="jina-clip-v1",
# choose `retrieval.passage` to get passage embeddings
task="retrieval.passage",
)
Step 4: Install and Set Up Pgvector
%pip install llama-index-vector-stores-postgres
from llama_index.core import VectorStoreIndex
from llama_index.vector_stores.postgres import PGVectorStore
vector_store = PGVectorStore.from_params(
database=db_name,
host=url.host,
password=url.password,
port=url.port,
user=url.username,
table_name="your_table_name",
embed_dim=1536, # openai embedding dimension
hnsw_kwargs={
"hnsw_m": 16,
"hnsw_ef_construction": 64,
"hnsw_ef_search": 40,
"hnsw_dist_method": "vector_cosine_ops",
},
)
Step 5: Build a RAG Chatbot
Now that you’ve set up all components, let’s start to build a simple chatbot. We’ll use the Milvus introduction doc as a private knowledge base. You can replace it with your own dataset to customize your RAG chatbot.
import requests
from llama_index.core import SimpleDirectoryReader
# load documents
url = 'https://raw.githubusercontent.com/milvus-io/milvus-docs/refs/heads/v2.5.x/site/en/about/overview.md'
example_file = 'example_file.md' # You can replace it with your own file paths.
response = requests.get(url)
with open(example_file, 'wb') as f:
f.write(response.content)
documents = SimpleDirectoryReader(
input_files=[example_file]
).load_data()
print("Document ID:", documents[0].doc_id)
storage_context = StorageContext.from_defaults(vector_store=vector_store)
index = VectorStoreIndex.from_documents(
documents, storage_context=storage_context, embed_model=embed_model
)
query_engine = index.as_query_engine(llm=llm)
res = query_engine.query("What is Milvus?") # You can replace it with your own question.
print(res)
Example output
Milvus is a high-performance, highly scalable vector database designed to operate efficiently across various environments, from personal laptops to large-scale distributed systems. It is available as both open-source software and a cloud service. Milvus excels in managing unstructured data by converting it into numerical vectors through embeddings, which facilitates fast and scalable searches and analytics. The database supports a wide range of data types and offers robust data modeling capabilities, allowing users to organize their data effectively. Additionally, Milvus provides multiple deployment options, including a lightweight version for quick prototyping and a distributed version for handling massive data scales.
Optimization Tips
As you build your RAG system, optimization is key to ensuring peak performance and efficiency. While setting up the components is an essential first step, fine-tuning each one will help you create a solution that works even better and scales seamlessly. In this section, we’ll share some practical tips for optimizing all these components, giving you the edge to build smarter, faster, and more responsive RAG applications.
LlamaIndex optimization tips
To optimize LlamaIndex for a Retrieval-Augmented Generation (RAG) setup, structure your data efficiently using hierarchical indices like tree-based or keyword-table indices for faster retrieval. Use embeddings that align with your use case to improve search relevance. Fine-tune chunk sizes to balance context length and retrieval precision. Enable caching for frequently accessed queries to enhance performance. Optimize metadata filtering to reduce unnecessary search space and improve speed. If using vector databases, ensure indexing strategies align with your query patterns. Implement async processing to handle large-scale document ingestion efficiently. Regularly monitor query performance and adjust indexing parameters as needed for optimal results.
pgvector optimization tips
To optimize pgvector in a Retrieval-Augmented Generation (RAG) setup, consider indexing your vectors using GiST or IVFFlat to significantly speed up search queries and improve retrieval performance. Make sure to leverage parallelization for query execution, allowing multiple queries to be processed simultaneously, especially for large datasets. Optimize memory usage by tuning the vector storage size and using compressed embeddings where possible. To further enhance query speed, implement pre-filtering techniques to narrow down search space before querying. Regularly rebuild indexes to ensure they are up to date with any new data. Fine-tune vectorization models to reduce dimensionality without sacrificing accuracy, thus improving both storage efficiency and retrieval times. Finally, manage resource allocation carefully, utilizing horizontal scaling for larger datasets and offloading intensive operations to dedicated processing units to maintain responsiveness during high-traffic periods.
OpenAI GPT-4o Mini optimization tips
To optimize the OpenAI GPT-4o Mini in a RAG setup, ensure concise input formatting by truncating or summarizing retrieved documents to stay within token limits. Use precise query phrasing to improve retrieval relevance, and filter redundant context to reduce noise. Leverage temperature and max_tokens parameters to balance creativity and focus. Cache frequent queries to minimize API calls and latency. Regularly validate outputs against ground truth to refine prompts and retrieval logic. Prioritize structured templates for consistent responses and implement error handling for rate limits or timeouts.
Jina-CLIP-v1 optimization tips
To optimize Jina-CLIP-v1 in a RAG setup, preprocess inputs by normalizing text and resizing images to match the model’s expected dimensions (e.g., 224x224). Use batch inference to maximize GPU utilization and enable mixed-precision (FP16) for faster processing. Fine-tune the model on domain-specific data to improve retrieval relevance. Cache frequently accessed embeddings to reduce redundant computations. Optimize vector indexing with approximate nearest neighbor (ANN) libraries like FAISS or HNSW for efficient similarity search. Regularly validate embedding quality using downstream task metrics to ensure alignment with retrieval goals.
By implementing these tips across your components, you'll be able to enhance the performance and functionality of your RAG system, ensuring it’s optimized for both speed and accuracy. Keep testing, iterating, and refining your setup to stay ahead in the ever-evolving world of AI development.
RAG Cost Calculator: A Free Tool to Calculate Your Cost in Seconds
Estimating the cost of a Retrieval-Augmented Generation (RAG) pipeline involves analyzing expenses across vector storage, compute resources, and API usage. Key cost drivers include vector database queries, embedding generation, and LLM inference.
RAG Cost Calculator is a free tool that quickly estimates the cost of building a RAG pipeline, including chunking, embedding, vector storage/search, and LLM generation. It also helps you identify cost-saving opportunities and achieve up to 10x cost reduction on vector databases with the serverless option.
Calculate your RAG cost
What Have You Learned?
Wow! What an incredible journey you've just embarked upon! After diving into this tutorial, you’re now well-versed in how to seamlessly integrate a powerful framework like LlamaIndex with the dynamic vector database Pgvector, alongside the advanced capabilities of the OpenAI GPT-4o mini and the embedding model Jina-Clip-v1. Together, these components form a robust Retrieval-Augmented Generation (RAG) system that not only enhances your data processing abilities but also elevates your AI projects to new heights. You’ve learned how to utilize LlamaIndex to structure and manage your data, harness Pgvector to swiftly access relevant information, and leverage the creative prowess of GPT-4o mini to generate insightful responses. The embedding model has been your secret weapon, allowing you to create rich, meaningful representations that resonate with your use cases.
But hold on, there’s more! Alongside the foundational knowledge, you’ve also picked up some awesome optimization tips to fine-tune your RAG pipeline for maximum efficiency. Plus, the free RAG cost calculator you discovered will make budgeting your projects a breeze! Think about all the incredible applications you can build with this knowledge: from chatbots that can hold intelligent conversations to personalized recommendation systems that anticipate user needs. Now's the time to put your newfound skills into action. So, roll up your sleeves, get creative, and most importantly, start building, optimizing, and innovating your own RAG applications. The possibilities are endless, and I can't wait to see what you create!
Further Resources
🌟 In addition to this RAG tutorial, unleash your full potential with these incredible resources to level up your RAG skills.
- How to Build a Multimodal RAG | Documentation
- How to Enhance the Performance of Your RAG Pipeline
- Graph RAG with Milvus | Documentation
- How to Evaluate RAG Applications - Zilliz Learn
- Generative AI Resource Hub | Zilliz
We'd Love to Hear What You Think!
We’d love to hear your thoughts! 🌟 Leave your questions or comments below or join our vibrant Milvus Discord community to share your experiences, ask questions, or connect with thousands of AI enthusiasts. Your journey matters to us!
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- Introduction to RAG
- Key Components We'll Use for This RAG Chatbot
- Step 1: Install and Set Up Llamaindex
- Step 2: Install and Set Up OpenAI GPT-4o mini
- Step 3: Install and Set Up jina-clip-v1
- Step 4: Install and Set Up Pgvector
- Step 5: Build a RAG Chatbot
- Optimization Tips
- RAG Cost Calculator: A Free Tool to Calculate Your Cost in Seconds
- What Have You Learned?
- Further Resources
- We'd Love to Hear What You Think!
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