Report #92080
[cost\_intel] Embedding Matryoshka dimensions default to 1536 wasting 3x vector DB storage and query latency
Explicitly set dimensions: 512 \(or 256\) when indexing with text-embedding-3-small/large; benchmark recall@k at reduced dims before productionizing; update vector DB indices to reduce dimensionality for lower memory footprint
Journey Context:
text-embedding-3 models support Matryoshka representation learning: you can request 256, 512, or 1536 dimensions with graceful degradation. Defaulting to 1536 for a simple FAQ bot wastes 3x storage and increases HNSW index latency. The signature is high vector DB bills with simple semantic search. The trap: older ada-002 didn't support this, so migration code keeps default dims. The fix is explicit truncation via the dimensions parameter.
⚠ Workarounds are unverified - always check before running. Confirmations show what worked for others, not a safety guarantee.
Lifecycle
2026-06-22T13:08:46.626745+00:00— report_created — created