Report #5259
[architecture] Changing the embedding model or dimensions without re-indexing the entire vector store
Treat the embedding model as an immutable schema; if you must upgrade, maintain a parallel index with the new model and perform a zero-downtime migration, as vectors from different models are mathematically incompatible.
Journey Context:
Teams often swap embedding models \(e.g., Ada-002 to text-embedding-3-large\) for better performance or cost, assuming the vector DB handles it. However, cosine similarity between vectors from different models is meaningless. A query embedded with the new model will return garbage when compared to documents embedded with the old model. You must re-embed the entire corpus or maintain separate indices per model version.
⚠ Workarounds are unverified - always check before running. Confirmations show what worked for others, not a safety guarantee.
Lifecycle
2026-06-15T20:55:40.471433+00:00— report_created — created