Amazon S3 Vectors introduces metadata pre-filtering for up to 5x higher recall on filtered search

Summary

• Added metadata pre‑filtering that evaluates filters before similarity search, boosting recall up to 5× for selective filters.
• Introduced $startsWith prefix match operator for metadata filtering (e.g., paths, URLs).
• New indexes use pre‑filtering by default; existing indexes can enable via UpdateIndexMode or a per‑query parameter, at no extra cost.