
RAG Explained For Beginners
KodeKloud
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Video Summary
Integrating an AI assistant with a company's extensive document server, potentially 500 gigabytes, presents a significant challenge compared to typical chat applications limited to a dozen files. Direct searching of such a vast dataset is inefficient. A more effective approach involves pre-processing documents by summarizing them into searchable chunks.
This method, known as Retrieval Augmented Generation (RAG), leverages large language models by converting documents into numerical representations called vector embeddings. These embeddings are stored in a vector database, allowing for semantic searches that match the meaning and context of a query rather than just keywords. The RAG process involves three key steps: retrieval, where relevant document chunks are semantically searched; augmentation, where these retrieved chunks are added to the AI's prompt at runtime to provide up-to-date information; and generation, where the AI uses this augmented information to produce an answer.
Implementing a RAG system requires careful consideration of several strategies, including how to chunk data (size and overlap), the choice of embedding model, and retrieval parameters. The optimal configuration depends heavily on the nature of the data, with legal documents requiring different chunking approaches than conversational transcripts. The practical implementation involves setting up a development environment, initializing a vector database, defining chunking and embedding strategies, ingesting documents, activating semantic search, and finally, launching a user interface for testing.
Short Highlights
- Integrating AI with large document repositories (500 GB) requires advanced methods beyond typical chat applications.
- Retrieval Augmented Generation (RAG) is a system that converts documents into semantic vector embeddings stored in a database for efficient, meaning-based searches.
- RAG involves three steps: retrieval of relevant information, augmentation of prompts with this information, and generation of AI responses.
- Key RAG implementation strategies include data chunking (e.g., size 500, overlap 100/400), embedding model selection (e.g., all-MiniLM-L6-v2), and retrieval settings.
- A practical RAG system setup involves Python, Chroma DB, Sentence Transformers, and Flask for a web interface, enabling answers grounded in private company data.
Key Details
Overcoming Large Document Integration Challenges [00:00]
- Connecting an AI assistant to a company's server with 500 gigabytes of documents is complex, as typical chat applications can only handle about a dozen files.
- Searching the entire 500 GB of documents for every user query is highly inefficient.
- Pre-processing by summarizing documents into searchable chunks is a more effective strategy.
This section highlights the difficulty of integrating AI with large datasets and introduces pre-processing as a solution to avoid inefficient direct searches.
From your experience, you know that typical chat applications can't accept more than a dozen files. So, you have to use a different method to allow the AI to search, read, and understand the entire files.
Understanding Vector Embeddings and Semantic Search [00:57]
- Large Language Models (LLMs) work with word embeddings, which convert human language into numerical representations.
- It's possible to store documents by preserving their semantics (meaning) as vector embeddings in a database.
- Splitting content into chunks in a vector database allows AI assistants to fit information into their context window and generate outputs.
- This method is called Retrieval Augmented Generation (RAG).
This part explains the foundational concept of vector embeddings and how they enable semantic search for AI applications.
So is it possible that instead of searching through the entire 500 GB of documents, we essentially store these documents by preserving the semantics which means meaning of those words into a vector embedding and store those into a database as vectors.
The Three Steps of Retrieval Augmented Generation (RAG) [01:48]
- RAG breaks down into three steps: Retrieval, Augmentation, and Generation.
- Retrieval: Documents are converted into vector embeddings and stored in a database. A user's question is also converted into an embedding and compared against document embeddings using semantic search, which matches based on meaning and context.
- Augmentation: Retrieved data is injected into the prompt at runtime, providing the AI with up-to-date, private information instead of relying solely on static pre-trained knowledge. This augmented knowledge is appended to the prompt.
- Generation: The AI assistant generates a response based on the semantically relevant data retrieved from the vector database and provided in the augmented prompt.
This section details the core mechanics of the RAG process, explaining how it retrieves, enhances, and generates answers.
Augmentation in rag refers to the process where the retrieved data is injected into the prompt at runtime.
Strategies for Setting Up a RAG System [04:00]
- Calibrating a RAG system is a skill that improves results.
- Chunking data before storing it in a vector database is critical for RAG's efficacy.
- Key strategies include:
- Chunking Strategy: Determining the size and overlap of each chunk.
- Embedding Strategy: Selecting the embedding model to convert documents into vector embeddings.
- Retrieval Strategy: Controlling similarity thresholds and adding filters to the dataset.
- The setup varies based on the data; legal documents require different chunking (preserving long paragraphs) than conversational transcripts (sentence-level chunking with high overlap).
This part emphasizes the importance of strategic choices in building a RAG system, particularly in data chunking and retrieval.
Knowing how to chunk your data before storing them into the vector database is a critical decision that will determine the efficacy of rag.
Practical Implementation of a RAG System [05:03]
- A practical demonstration involves setting up a Python virtual environment and installing packages like Chroma DB, Sentence Transformers, OpenAI, and Flask.
- The process includes reviewing document vaults (e.g., employee handbook, product specs), initializing a vector database (Chroma DB with a collection named
tech_corps_docs
), and defining a chunking strategy (size 500, overlap 100). - Embedding involves using a model like
all-MiniLM-L6-v2
to encode sentences and compute similarities, where questions and documents become vectors. - Ingestion involves embedding each document chunk and storing vectors with metadata into the vector database.
- Semantic search is activated by building a search engine script that embeds queries and fetches top results by similarity.
- A simple web interface using Flask on port 5000 allows users to test the system, with answers grounded in the private documents and sources provided.
- Key parameters for this specific setup include the model
all-MiniLM-L6-v2
, chunking size 500 with overlap 400 (for testing) and stride 400 (for ingestion), Chroma persistence, and a similarity threshold to reduce hallucinations.
This section walks through the hands-on steps of building and testing a RAG system, illustrating its components and functionality.
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