Using vector databases for GenAI

Modern generative AI is powered by more than models—it runs on fast data. From chatbots to real-time personalization, high-performing AI systems rely on vector databases to store, retrieve, and search the embeddings that fuel every smart response.

If you’re building with generative AI or retrieval-augmented generation (RAG), you’re probably already generating embeddings. But where you store and search them matters—a lot. That’s where vector databases come in.

Let’s break down what a vector database is, why traditional options fall short, and how Redis delivers real-time AI pipelines at scale.

What is a vector database?

A vector database is a system purpose-built to store, index, and search high-dimensional vectors—like the embeddings generated by AI models for text, images, video, and audio.

Think of vectors as numerical fingerprints. When an AI model converts a sentence, image, or other input into a vector, it’s mapping that input to a point in high-dimensional space. These points capture meaning, context, and relationships—allowing AI systems to perform semantic search, content generation, and similarity matching.

A vector database stores those fingerprints, indexes them for fast retrieval, and lets you search by similarity. Instead of asking “what row has this ID?” you’re asking, “what stored vectors are most similar to this one?”

That kind of query—known as vector search or approximate nearest neighbor (ANN) search—is fundamentally different from SQL or NoSQL queries. It demands specialized indexing (like HNSW or IVF), and most traditional databases just aren’t built for it.

Why are vector databases important for generative AI?

Generative AI doesn’t just generate—it retrieves, ranks, compares, and refines. Every step of that process relies on vector representations.

When you ask a chatbot a question, it:

1. Embeds your query into a vector.
2. Searches a database for semantically similar content.
3. Feeds relevant results into the model for a response.

That middle step—semantic vector search—is where vector databases shine. Without it, models are guessing blind or relying on limited context.

Real-time AI needs real-time search

Latency matters in generative systems. If your app is generating personalized copy or answering customer questions, every millisecond counts.

Vector databases are critical because they:

• Handle high-dimensional vector search efficiently
• Scale to millions (or billions) of embeddings
• Support low-latency, high-throughput queries
• Integrate with modern AI pipelines in real time

Without a purpose-built vector database, you’re likely to hit bottlenecks fast—and those milliseconds add up. Faster queries mean more revenue in ecommerce, quicker responses in CX, and lower churn in apps where every interaction counts.

Challenges of traditional databases for generative AI workloads

SQL and general-purpose NoSQL databases weren’t designed for vector search. You can try to bolt on support with hacks—store vectors as blobs, run brute-force comparisons—but it doesn’t scale, and it’s definitely not fast.

Here’s why traditional databases struggle:

• No native vector indexing: SQL engines and document stores lack built-in support for vector similarity indexes like HNSW or Annoy.
• Inefficient filtering: Searching across millions of high-dimensional vectors is slow without purpose-built indexes.
• Latency overhead: Even with caching, you often can’t hit the sub-millisecond latency required for real-time AI.
• Complex architectures: You end up stacking services (search, cache, database) just to deliver a single vector lookup.

And bolting on vector capabilities doesn’t solve the underlying issue: general-purpose databases weren’t designed for this. You need a system built for vector data from the ground up—or a fast, scalable platform like Redis that does both.

Use cases for vector databases in generative AI

Vector databases unlock a wide range of generative AI use cases. If you’re embedding anything—text, images, user profiles—you’ll likely benefit from fast similarity search.

Retrieval-augmented generation (RAG) pipelines

Power RAG workflows by storing and retrieving context embeddings in real time. Vector databases make it easy to fetch relevant documents or data for your model before generation—enabling accurate, context-aware responses at scale.

Personalized recommendations

Recommend products, content, or offers based on vector similarity between a user’s behavior and your item catalog. Vectors let you match based on meaning, not just metadata.

Chatbots & virtual assistants

Use embeddings to retrieve relevant knowledge, responses, or conversation history—making your bots more context-aware and human-like.

Semantic search engines

Replace keyword search with vector similarity search to let users find content based on meaning, not exact matches.

Content creation & editing

Enable models to generate or refine content with reference to semantically similar assets—like past campaigns, documents, or styles.

Quantitative forecasting

Embed time series data or metrics and find patterns across high-dimensional vectors. Useful for finance, logistics, or trend analysis.

All of these use cases require fast vector storage and lookup. Redis handles that with sub-millisecond performance—even at scale.

How Redis powers generative AI with vector databases

You already know Redis for speed. What you might not know: Redis combines cache, database, vector search, and model serving in a single real-time engine—eliminating the latency and complexity of stitching separate systems together.

Whether you’re embedding text, running similarity search, or powering a real-time pipeline, Redis gives you the building blocks to do it fast.

Native vector support

Redis supports vector similarity search natively through the VECTOR data type in RediSearch. You get:

• Approximate nearest neighbor (ANN) algorithms like HNSW
• Support for cosine, Euclidean, and dot product similarity
• Filtered search combining metadata & vector scores
• Indexing at scale with real-time updates

No bolted-on vector layers. Just fast, native vector support.

Built-in AI integration with RedisVL

RedisVL gives developers a clean, Python-first interface for building AI retrieval workflows on top of Redis:

• Store and query vector embeddings using Redis’s high-performance vector search
• Manage schemas for documents, metadata, and embeddings in a unified way
• Build RAG pipelines that combine vector search, caching, and structured retrieval
• Reduce pipeline overhead with a single, fast data layer for context retrieval

Sub-millisecond vector search at scale

Redis is designed for low-latency, high-throughput workloads. You can store millions of vectors and query them in real time—without waiting for external services.

That makes Redis ideal for:

• Chatbot memory and context recall
• Real-time recommendations
• Inference-time content retrieval
• Generative UX features like autocomplete, summarization, or rewriting

Example: Building a generative AI pipeline with Redis

Here’s what a simple generative AI stack with Redis looks like:

1. Embed data

Use an embedding model (e.g. OpenAI, Cohere, or in-house) to convert content to vectors.

2. Store vectors in Redis

Store embeddings using the VECTOR data type, along with any metadata you need (title, ID, type, etc.).

3. Search by similarity

When a user submits input, embed it and run a similarity search in Redis to retrieve the most relevant content.

4. Generate a response

Feed the results into your LLM to generate a response with relevant context.

All of this can happen in milliseconds—with a single platform handling storage, search, and response.

Redis isn’t just fast. It’s AI-native.

If you’re serious about generative AI, you need more than a good model. You need a data architecture that keeps up—and delivers real results. Redis helps reduce infrastructure costs, speed up product launches, and improve customer experiences by bringing data, cache, and AI together in real time.

Redis delivers:

• Real-time vector search with sub-millisecond latency
• High-throughput pipelines built for modern workloads
• Built-in model serving with RedisAI
• Flexible deployment on cloud, edge, or hybrid infra

That’s why teams across fintech, healthcare, gaming, and retail are building AI-native apps on Redis.

Ready to scale your generative AI pipeline?

Redis makes it easy to get started with vector search and real-time AI.

→ Download the O’Reilly report: Managing Memory for AI Agents

→ Try Redis for free

→ Explore vector search docs

→ See the benchmark results