artificial intelligence

What is retrieval augmented generation? How it works

You ask your AI a simple question about last quarter’s performance, and it confidently tells you revenue grew 15%. When you double-check with your analyst and hear the real number is 8%, you start to see the problem. It’s not that the model is trying to mislead you. It’s operating on incomplete information.

That gap is exactly why retrieval augmented generation is getting so much attention. RAG gives AI a way to reference live, verified data before it answers, so responses reflect what’s actually happening in your business, not what the model remembers from training.

Instead of debating whether the AI “sounds right,” you get answers grounded in facts. And once you understand that shift, the rest of RAG’s value becomes a lot clearer. Let’s start with what RAG actually is.

What is retrieval augmented generation?

Retrieval Augmented Generation (RAG) is a technique that gives large language models (LLMs) access to external, real-time information, leading to more accurate and trustworthy answers. Unlike standard AI models that only know what they learned during their initial training, RAG systems can look up current facts before responding.

Think of it as the difference between a closed-book and an open-book exam:

  • A standard LLM built on transformer architecture takes a closed-book test, relying only on what it has memorized. 

  • A RAG system gets an open book, allowing it to find and use the most relevant, up-to-date information to answer your questions.

Why does RAG matter for your AI strategy?

If you're bringing AI into your organization, you've probably asked the big question: Can you actually trust its answers? RAG technology is what helps solve this problem by grounding AI responses in verifiable facts, which is why so many data leaders are paying attention to it.

The trust problem with standard LLMs

Without RAG, standard LLMs have a few key weaknesses that make them risky for you to use in your business:

  • Knowledge cut-off dates: They're unaware of recent data or events

  • Hallucinations: They can make up plausible but false information

  • Limited context: They lack access to your company's specific data

As Amit Prakash, Co-founder and CTO of ThoughtSpot, puts it in an episode of The Data Chief

"In particular, one of the things that we've realized working on this for so long is that number one trust is so important in the data space. You cannot put a product in front of people that's supposed to answer data questions, and it gets it wrong." 

How RAG solves the hallucination problem

RAG reduces the risk of AI making things up by forcing it to check its facts first. Instead of just generating an answer from its memory, a RAG system retrieves relevant information from a trusted source and uses that information to construct the answer.

Standard LLM

RAG System

Generates from memory

Retrieves then generates

May hallucinate facts

Cites actual sources

Static knowledge

Dynamic, updated knowledge

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How does retrieval augmented generation work?

The RAG process comes down to three steps: retrieval, augmentation, and generation. Together, they give an AI agent the context it needs to have a useful, fact-based conversation with you about your data.

For example, an AI agent like Spotter uses these principles to let you ask questions in natural language and get trusted answers that are backed by your company's live data. Rather than waiting for analysts to build static reports, you can simply ask, "What caused the revenue spike last Tuesday?" and get an immediate response with cited sources.

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1. Retrieving relevant information

This is the search phase. When you ask a question, the system first scans a specified knowledge base for information related to your query, whether that’s company documents, policies, live databases, or vector-matched results that surface the most relevant content.

2. Augmenting the prompt with context

Next comes the context-building phase. The information retrieved in step one gets combined with your original question to form a richer prompt for the LLM. This gives the model the factual grounding it needs to answer accurately.

3. Generating accurate responses

Finally, the model uses that augmented prompt to produce an answer. Because it now has both your question and the relevant supporting facts, the response is rooted in real data instead of relying solely on the model’s training memory.

What are the key benefits of RAG for you?

Now that you understand how RAG works, let's look at why it's becoming so important for your work. RAG directly addresses some of the biggest pain points you face when trying to adopt AI.

1. Improved accuracy and trust

If you're like most leaders, the number one barrier to AI adoption is a lack of trust. RAG helps build that trust by providing answers that are backed by verifiable sources, giving you the confidence to make decisions based on what the AI tells you.

2. Always current information

Business doesn't stop, and your data is always changing. RAG systems connect to live data sources, which is a huge advantage in fast-moving environments where decisions need to be based on the absolute latest information 

3. Cost-effective AI implementation

Continuously retraining an LLM on new data is expensive and time-consuming, which can drive up costs. This is where FinOps for LLMs becomes important. With RAG, you can simply update your knowledge base, which is a much cheaper and more practical way to keep your AI's knowledge current.

See how RAG-powered analytics can give you trusted answers from your live data. Start free trial

RAG vs traditional LLMs

Choosing between a RAG system and a traditional LLM depends entirely on your goals. Here's how they compare:

Aspect

Traditional LLM

RAG System

Knowledge source

Training data only

Training data + external databases

Information currency

Fixed at training time

Real-time updates possible

Best for

General knowledge, creative tasks

Domain-specific, factual answers

Implementation complexity

Simpler to start

More flexible but requires more setup

Types of RAG systems

As RAG has gained traction, a few different approaches have emerged to support varying levels of complexity and control.

1. Naive RAG

This is the simplest version, built on the basic retrieve-then-generate workflow. It works as an entry point but can surface irrelevant or loosely related information, which means the model occasionally produces weaker answers.

2. Advanced RAG

Advanced RAG improves on the naive approach by adding steps like re-ranking retrieved documents and optimizing the query itself. These extra steps help make sure the information passed to the LLM is highly relevant, resulting in better answers.

3. Modular RAG

Modular RAG offers the most flexibility. Each component, like retrieval, re-ranking, prompt construction, and generation, can be swapped or tuned individually. For teams with specific requirements or unique data environments, this approach makes it easier to tailor the workflow to their needs.

Common RAG use cases and applications

Because of its flexibility, RAG is being used in a wide range of business functions. Here are a few practical examples you might see in your own organization.

1. Customer service and support

RAG can power customer service chatbots that provide accurate answers based on the latest product information and company policies. For example, a customer can ask about a recent return policy change, and the chatbot can retrieve and cite the new update.

2. Business intelligence and analytics

In the era of augmented analytics, RAG is changing how people interact with business data. Instead of building complex reports with traditional BI, you can use a platform like the ThoughtSpot Analytics Platform to simply ask questions in plain language.

Act-On’s marketing teams were buried in scattered systems and slow reporting cycles. After embedding ThoughtSpot's search experience, customer report usage rose 60 percent, and they shipped industry-specific Liveboards in under two months, a pace that would have been impossible with traditional dashboards.

3. Knowledge management systems

Companies with large internal knowledge bases often struggle with search. RAG can layer a conversational interface on top of those systems so employees can ask questions directly and quickly surface the information they need.

Building trust through retrieval augmented generation

For AI to be widely adopted, people have to trust it. RAG takes a major step in that direction by grounding answers in verifiable data, but the technology on its own isn’t the full solution.

As Jeremy Kahn noted on The Data Chief,

"We don't talk enough about how to train people to use AI software. The organizations that think hardest about that are going to be very successful."

Trust ultimately depends on a strong governance foundation, and that’s where an Agentic Semantic Layer comes in. Think of it as the operational brain behind your AI: it defines business terms, applies access rules, and ensures every answer aligns with how your company measures and talks about its data.

By standardizing how the system interprets core concepts, the semantic layer removes ambiguity. When someone asks about “revenue,” the AI doesn’t guess which table to pull from or how to calculate the metric. 

It refers to a shared, governed definition, the same one used across finance, sales, and analytics. That consistency prevents teams from working with conflicting numbers and strengthens trust in every answer the AI produces.

Making RAG work for your analytics and AI initiatives

RAG offers a practical path forward for you to use AI responsibly and effectively in your organization. It bridges the gap between the broad knowledge of LLMs and the specific, real-time data your business runs on.

By grounding every answer in verifiable facts, RAG delivers a clear return on all three fronts. Modern analytics platforms are already putting these principles to work to deliver trusted, governed AI experiences. 

If you want to see how this shift can move your team from static reporting to dynamic, conversational insights, you can start a free ThoughtSpot trial.

FAQs about retrieval augmented generation

1. How do you measure RAG system performance?

RAG performance is typically measured by looking at both the relevance of the retrieved information and the quality of the final generated answer. Common metrics include precision and recall for retrieval, along with user satisfaction scores for the overall experience.

2. What's the difference between naive RAG and advanced RAG implementations?

Naive RAG is a simple, two-step process of retrieving and generating, while advanced RAG adds extra steps like re-ranking search results to improve relevance. Advanced RAG generally produces more accurate answers, especially for complex questions.

3. How does RAG maintain data security and governance controls?

RAG systems can enforce your existing security rules at the retrieval step. This means the AI will only access and use data that you are already permitted to see, maintaining data security.

4. What infrastructure requirements does RAG implementation have?

A typical RAG setup includes a vector database to store and search for information efficiently, an LLM to generate answers, and a system to manage the workflow. Many cloud providers now offer services that simplify this setup.