# Vector Database Comparison and Configuration

## Overview
Vector databases store and efficiently retrieve document embeddings for semantic search in RAG systems.

## Popular Vector Database Options

### 1. Pinecone
- **Type**: Managed cloud service
- **Features**: Scalable, fast queries, managed infrastructure
- **Use Case**: Production applications requiring high availability

### 2. Weaviate
- **Type**: Open-source, hybrid search
- **Features**: Combines vector and keyword search, GraphQL API
- **Use Case**: Applications needing both semantic and traditional search

### 3. Milvus
- **Type**: High performance, on-premise
- **Features**: Distributed architecture, GPU acceleration
- **Use Case**: Large-scale deployments with custom infrastructure

### 4. Chroma
- **Type**: Lightweight, easy to use
- **Features**: Local deployment, simple API
- **Use Case**: Development and small-scale applications

### 5. Qdrant
- **Type**: Fast, filtered search
- **Features**: Advanced filtering, payload support
- **Use Case**: Applications requiring complex metadata filtering

### 6. FAISS
- **Type**: Meta's library, local deployment
- **Features**: High performance, CPU/GPU optimized
- **Use Case**: Research and applications needing full control

## Configuration Examples

### Pinecone Setup
```python
import pinecone
from langchain.vectorstores import Pinecone

pinecone.init(api_key="your-api-key", environment="us-west1-gcp")
index = pinecone.Index("your-index-name")
vectorstore = Pinecone(index, embeddings.embed_query, "text")
```

### Weaviate Setup
```python
import weaviate
from langchain.vectorstores import Weaviate

client = weaviate.Client("http://localhost:8080")
vectorstore = Weaviate(client, "Document", "content", embeddings)
```

### Chroma Local Setup
```python
from langchain.vectorstores import Chroma

vectorstore = Chroma(
    collection_name="my_collection",
    embedding_function=embeddings,
    persist_directory="./chroma_db"
)
```

## Selection Criteria

1. **Scale**: Number of documents and expected query volume
2. **Performance**: Latency requirements and throughput needs
3. **Deployment**: Cloud vs on-premise preferences
4. **Features**: Filtering, hybrid search, metadata support
5. **Cost**: Budget constraints and operational overhead
6. **Maintenance**: Team expertise and available resources

## Best Practices

1. **Indexing Strategy**: Choose appropriate distance metrics (cosine, euclidean)
2. **Sharding**: Distribute data for large-scale deployments
3. **Monitoring**: Track query performance and system health
4. **Backups**: Implement regular backup procedures
5. **Security**: Secure access to sensitive data
6. **Optimization**: Tune parameters for your specific use case