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# Vector Search

## Vector Search in ScyllaDB

Vector Search is a powerful method for efficiently searching and retrieving
high-dimensional data based on similarity rather than exact matches. It is
particularly useful in AI and machine learning applications, where data is
often represented as vectors — mathematical representations of objects such as
text, images, audio, or video. In these applications, you typically need to
retrieve data that is similar to a given query, rather than relying on
keyword-based search or exact matches.

ScyllaDB’s Vector Search feature allows you to store, index, and query
high-dimensional vector data at scale.
Vector Search is built to work within your existing ScyllaDB infrastructure,
taking advantage of its high-performance and highly available architecture.

### Common Use Cases

* **Semantic search** — Find documents or passages that match the *meaning*
  of a query, not just the keywords.
* **Retrieval-Augmented Generation (RAG)** — Provide relevant context to an
  LLM by retrieving similar documents from a vector store.
* **Recommendation systems** — Find items similar to those a user has
  interacted with.
* **Image and audio search** — Find visually or acoustically similar media.
* **Anomaly detection** — Identify outliers far from all clusters in vector
  space.
* **Deduplication** — Find near-duplicate records by identifying vectors that
  are very close together.

See [Common Use Cases](https://cloud.docs.scylladb.com/stable/vector-search/vector-search-concepts.md#vs-concepts-use-cases) in the Concepts page for
more details.

## Getting Started

* [Quick Start Guide](https://cloud.docs.scylladb.com/stable/vector-search/vector-search-quick-start.md)
  <br/>
  Walk through setting up a vector-enabled table, inserting data, and running
  your first similarity search in minutes.
  <br/>

## Understanding Vector Search

* [Vector Search Concepts](https://cloud.docs.scylladb.com/stable/vector-search/vector-search-concepts.md)
  <br/>
  Architecture overview, HNSW algorithm, CDC-based indexing, and data flow
  between storage and vector search nodes.
  <br/>
* [Glossary](https://cloud.docs.scylladb.com/stable/vector-search/vector-search-glossary.md)
  <br/>
  Definitions of key terms including ANN, HNSW, embeddings, similarity
  functions, quantization, filtering, and more.
  <br/>

## Deployment and Operations

* [Vector Search Deployments](https://cloud.docs.scylladb.com/stable/vector-search/vector-search-clusters.md)
  <br/>
  Create, enable, resize, disable, and monitor Vector Search clusters
  in ScyllaDB Cloud via the UI or API.
  <br/>
* [Sizing and Capacity Planning](https://cloud.docs.scylladb.com/stable/vector-search/vector-search-sizing.md)
  <br/>
  Estimate memory requirements, understand quantization impact, and choose
  instance types for your workload.
  <br/>
* [Security](https://cloud.docs.scylladb.com/stable/vector-search/vector-search-security.md)
  <br/>
  Authentication, authorization, service-level isolation, and network
  security for vector search.
  <br/>

## Working with Vectors

* [Working with Vector Search](https://cloud.docs.scylladb.com/stable/vector-search/work-with-vector-search.md)
  <br/>
  CQL usage guide covering the vector data type, vector indexes, similarity
  functions, index tuning, ANN queries, and driver integration.
  <br/>
* [Vector Search with Alternator](https://cloud.docs.scylladb.com/stable/vector-search/vector-search-alternator.md)
  <br/>
  Use Vector Search through the DynamoDB-compatible Alternator API, with
  Python examples and a feature-availability comparison with CQL.
  <br/>
* [Filtering Vector Search Results](https://cloud.docs.scylladb.com/stable/vector-search/vector-search-filtering.md)
  <br/>
  Combine similarity search with metadata constraints using global and local
  vector indexes.
  <br/>
* [Quantization and Rescoring](https://cloud.docs.scylladb.com/stable/vector-search/vector-search-quantization.md)
  <br/>
  Reduce index memory usage with quantization (f16, i8, b1) and recover
  precision with oversampling and rescoring.
  <br/>
* [LangChain and CassIO Compatibility](https://cloud.docs.scylladb.com/stable/vector-search/vector-search-langchain.md)
  <br/>
  Use the LangChain Cassandra connector (CassIO) with ScyllaDB through
  Storage Attached Index (SAI) compatibility, including requirements,
  limitations, and a runnable RAG example.
  <br/>

## Troubleshooting and Reference

* [Troubleshooting](https://cloud.docs.scylladb.com/stable/vector-search/vector-search-troubleshooting.md)
  <br/>
  Common issues and solutions for index creation, query results, data
  insertion, performance, and connectivity.
  <br/>
* [FAQ](https://cloud.docs.scylladb.com/stable/vector-search/vector-search-faq.md)
  <br/>
  Frequently asked questions about similarity functions, dimensions,
  latency, filtering, quantization, and more.
  <br/>
* [Reference](https://cloud.docs.scylladb.com/stable/vector-search/reference-vector-search.md)
  <br/>
  Technical reference for instance types, CQL syntax, index options,
  and Cloud API endpoints.
  <br/>

## Examples

* [Example Applications](https://vector-search.scylladb.com/)
  <br/>
  Learn how to use ScyllaDB Vector Search to build RAG applications,
  semantic caching layers, and how it integrates with popular LLM
  libraries like LlamaIndex and LangChain.
  <br/>
* [LangChain and CassIO Compatibility](https://cloud.docs.scylladb.com/stable/vector-search/vector-search-langchain.md)
  <br/>
  Run the LangChain Cassandra connector against ScyllaDB, with a complete
  Retrieval-Augmented Generation (RAG) example.
  <br/>
