Error: DynamoDB no attribute schema defined

“No attribute schema defined” is not enough to conclude that a DynamoDB table has no schema. Tables require a primary key, but non-key attributes are flexible. Determine whether the message comes from table creation or a client-side mapper before changing the table.

1. For CreateTable validation, ensure every attribute used by the table or index key schema has a matching AttributeDefinition with type S, N, or B. Do not list ordinary non-key fields there.
2. For Java Enhanced Client, supply the correct TableSchema, either from annotated bean metadata or an explicit schema builder. Verify key annotations and converters.
3. For another mapper, inspect its model metadata and registration. A plain deserialized object may not carry the class or schema metadata the mapper expects.
4. Use DescribeTable and a minimal low-level operation to distinguish deployed key metadata from application mapping failures.

Do not recreate a data-bearing table because an application mapper lacks a field schema. The exact library producing this phrase is not established without the stack trace; apply the documented mapping rules for the library actually in use.

See Java model mapping and AWS documentation.