DynamoDB quietly changed how it bills vector reads

A developer found that between October 9 and October 22, 2026, DynamoDB began charging 1 read unit instead of 2 for a vector item. AWS has not announced the change; writes and the 400KB item limit still use the stored size.

• Test in eu-west-2: a read cost 2 units on October 9 and 1 on October 22
• All 32 regions with vector search now bill the read at 1 unit
• The 400KB item limit still uses the stored size
• Emulators Dynoxide, Floci and ExtendDB still reproduce the old behavior