vector-database
Installation
SKILL.md
Vector Database Skill
Iron Law
Pin dimensions at model selection. The embedding dimension must match the model exactly and is set once — changing models requires a full re-embedding migration. Store embedding_model varchar(100) alongside every vector column so the model is always auditable.
Embedding Model Selection
Choose model before writing any schema. Dimension determines index shape.
| Model | Dims | Notes |
|---|---|---|
text-embedding-3-small (OpenAI) |
1536 | Best cost/quality for most cases |
text-embedding-3-large (OpenAI) |
3072 | Max OpenAI quality, 2× cost |
embed-english-v3.0 (Cohere) |
1024 | Native Weaviate integration |
voyage-3-large (Voyage AI) |
1024 | Top retrieval benchmarks |
nomic-embed-text (local) |
768 | Free, on-prem, no API call |