Vector Database Comparison: MySQL vs Pinecone vs Weaviate

After reading this, you’ll know which vector database is right for your site — and whether you even need one. Most small-to-medium WordPress sites don’t need a vector database at all.

In this article: What is a Vector Database? · Your Options in AIWU · Side-by-Side Comparison · When to Use Which · Switching Later

Before You Start

You’ll need:

• Basic understanding of embeddings (Embeddings in 10 Minutes)
• Understanding of training approaches (Fine-Tuning vs Embeddings)

What is a Vector Database? (Plain English)

When AIWU’s AI searches your knowledge base, it doesn’t search for exact keyword matches. Instead, it converts your content into numerical “fingerprints” (called embeddings) that capture meaning. A vector database stores and searches these fingerprints.

The difference in practice: with keyword search, “broken checkout” won’t find an article titled “payment errors.” With vector/semantic search, it will — because they mean the same thing.

Your Options in AIWU

AIWU supports three storage approaches for AI-powered search:

1. WordPress Database (MySQL) — Default

Embeddings stored directly in your WordPress database. No external service needed.

2. Pinecone

External cloud vector database. Dedicated vector search infrastructure, hosted by Pinecone.

3. Weaviate

Open-source vector database. Can be self-hosted or used as a cloud service.

Side-by-Side Comparison

When to Use Which

Use MySQL (Default) if:

• You have fewer than 50,000 products or knowledge base articles
• You’re just getting started with AI search
• You want zero additional cost
• Your search response time is acceptable (under 2 seconds)

This describes the majority of WordPress sites. Start here.

Switch to Pinecone if:

• You have 50,000+ products or articles
• Search is slowing down and affecting user experience
• You’re running high traffic (100+ concurrent searches)
• You want managed infrastructure with no server admin

Switch to Weaviate if:

• You need full data control for compliance reasons (healthcare, finance)
• You have technical staff who can maintain a self-hosted service
• You want to avoid ongoing subscription costs for external services
• You’re already using Weaviate for other infrastructure

Performance Numbers

Approximate search latency on a typical shared hosting setup:

Note: Actual performance depends on your server, hosting plan, and query complexity.

Switching Vector Databases Later

You can change your vector database at any time. The process:

1. Go to AI Copilot → Training → Settings → Vector Database
2. Select the new database and enter credentials
3. Click Migrate Embeddings
4. AIWU will transfer existing vectors to the new database

Migration time: roughly 1-2 minutes per 1,000 vectors. Your site stays live during migration — AIWU continues using the old database until migration completes, then switches automatically.

Setting Up Pinecone (if you decide to switch)

1. Create a free account at pinecone.io
2. Create an index: Indexes → Create Index
   • Dimensions: 1536 (for OpenAI embeddings) or 768 (for other models)
   • Metric: cosine
3. Go to API Keys and copy your key
4. In AIWU: AI Copilot → Training → Settings → select Pinecone → paste API key + index name
5. Click Test Connection, then Migrate Embeddings

What’s Next

• 🟢 Optimize your training data: Training Data Best Practices
• 🟡 Connect training to your chatbot: Train Your Chatbot with Embeddings
• 🔵 Security & data handling: Security & Privacy: How AIWU Handles Your Data

Last verified: AIWU v.4.9.2 · Updated: 2026-02-25