[LeeroyHannigan]

Summary

Three measured sentence and shape fixes on the stream and UpdateTable paths, found while reviewing #515. Every expected answer was measured on Amazon DynamoDB on 2026-10-24 and 2026-10-25; the rows are in the wire tests.

Closes #517, closes #519, closes #520.

Change

#517. DescribeStream returns CreationRequestDateTime on every stream, enabled or disabled; ExtendDB omitted it on every backend. The value is derived from the stream label: stream_label_creation_date_time (crates/storage/src/util/arn.rs) parses the 23-byte label every backend writes today and the 19-byte label SQLite, PostgreSQL and MongoDB wrote on v0.1.3 to v0.1.13 and Cassandra up to v0.1.14, so a stream enabled on those versions and never re-enabled reports the member too. The engine sets it in handle_describe_stream, the one response-boundary site, so all four backends return it. On the service the member is a stored request time that preceded the label's instant by 0 to 13 ms in three measurements; on ExtendDB the two name the same millisecond.

#519. UpdateTable with StreamEnabled: true and no StreamViewType now answers the service's If stream is being enabled then UpdateViewType is required. The service reports a defective GSI Create and a PROVISIONED billing mode without throughput before the missing view type, and the view type before the table lookup; the check moved to after the billing and index rules. The throughput sentence is now the service's ProvisionedThroughput must be specified when BillingMode is PROVISIONED (ExtendDB said when changing BillingMode to PROVISIONED).

#520. A GSI Create whose key attribute is not in AttributeDefinitions gets one of three sentences by the member's shape: absent, AttributeDefinitions is not specified for index: <name> (the first Create in request order, even when the key is the table's own hash key); present and lacking the key, the Keys: [..], AttributeDefinitions: [..] sentence; present and empty, Invalid KeySchema: Some index key attribute have no definition. ExtendDB rendered the second for every shape. The CreateTable path is untouched; it has its own copy of the check in crates/core.

The update_table unit tests moved to crates/engine/src/update_table_tests.rs unchanged (the file had crossed 600 lines).

Tests

• tests/python/test_update_table_sentences.py (8 rows, dual-target): the two UpdateTable: the missing StreamViewType sentence differs from the service #519 shapes, the three UpdateTable GSI create on an undefined key attribute: sentence differs from the service #520 shapes, the CreateTable shape, and the two validation-order rows. 8 of 8 on the live service and on a SQLite dev-mode server.
• tests/python/test_streams.py::TestDescribeStream::test_creation_request_date_time_is_the_label_instant: the member is present on an enabled stream and after a disable, and equals the label's instant. The row accepts an omitted StreamSpecification after the disable, which is what the service returns and what fix(streams): disabling a stream closes its shards; enabling makes a new one #515 brings to ExtendDB.
• Unit: parser rows for the 23-byte and 19-byte labels, leap day, year end, and eight refused shapes including non-ASCII; the three validators called directly. Storage 127, engine 181, core 519.
• Controls: a binary with the two handler calls removed fails the UpdateTable: the missing StreamViewType sentence differs from the service #519 and DescribeStream omits CreationRequestDateTime #517 wire rows and passes every unit test (the wire rows are the pin on the wiring); a binary reverted to main fails 5 of the 7 rows that existed at the time and passes the 2 that encode behaviour main already had.

Measured, not changed here

• The Keys: [..] and AttributeDefinitions: [..] lists: on the service Keys carries every key of the index (not the missing one), two missing keys with a non-empty member is Invalid KeySchema, and both lists come out in an order that is neither the request's nor alphabetical. Pre-existing on both the CreateTable and UpdateTable paths; filed separately. The rows here use one-key shapes where the order does not arise.
• AttributeDefinitions that redefines the table's own key with another type is accepted by the service, which keeps the original type; a duplicated definition is refused with Attribute Name is duplicated: <name>. ExtendDB accepts both. Filed separately.

Merge notes for #515

Six files conflict with fix/482-stream-disable-closes-shards; the resolution: drop #515's inline enable check in handle_update_table (this branch's validate_stream_specification carries the measured sentence and runs after the index rules) and keep #515's disable rule after it; keep both validate_stream_specification and stream_change_companion; union the two test blocks in update_table_tests.rs; take #515's side for the four backend describe_stream bodies and add creation_request_date_time: None, to the one StreamDescription literal in stream_lineage.rs. After both land: stream_lineage::label_millis and stream_label_creation_date_time parse the same label, so one parser should define the shape and carry the 19-byte arm; #515's storage-side copy of the view-type rule still has the old sentence (unreachable, since the engine check runs first) and should take the measured one; and the #517 wire row gains assert desc["StreamStatus"] == "DISABLED" on the post-disable DescribeStream, which no backend answers before #515.