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DynamoDB

live (AWS) 25 recorded runs

100%
correct, across 873 of 873 operations
Tier 1 100%
Tier 2 100%
Tier 3 100%

Fully supports

Operation areas this target implements completely - every test passes, nothing skipped. Areas it only partly implements, or gets wrong, are in “Where it falls short” below.

  • batchGetItem tier 1
  • batchWriteItem tier 1
  • createTable tier 1
  • deleteItem tier 1
  • deleteTable tier 1
  • describeTable tier 1
  • getItem tier 1
  • listTables tier 1
  • putItem tier 1
  • query tier 1
  • scan tier 1
  • updateItem tier 1
  • updateTable tier 1
  • account tier 2
  • backups tier 2
  • contributorInsights tier 2
  • export tier 2
  • kinesis tier 2
  • partiql tier 2
  • resourcePolicy tier 2
  • streams tier 2
  • tags tier 2
  • transactions tier 2
  • ttl tier 2
  • updateTable tier 2
  • error-messages tier 3
  • legacy-api tier 3
  • limits tier 3
  • validation-ordering tier 3

Conformance over time

Real DynamoDB is the baseline every other target is measured against, so it's 100% across every run by definition, not a result that moves.

Run history

Run Total Movement
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Suite on

Grew to 873 tests, up 49, all characterised against real DynamoDB in eu-west-2. New coverage in three areas:

  • ConsumedCapacity: the transactional read/write split on a same-token replay and on ExecuteTransaction, and a correction that single-item operations report the aggregate CapacityUnits and omit the split, which is transactional-only.
  • Empty-binary key values: rejected as a top-level ValidationException on every path, including secondary-index keys and inside transactions, mirroring the empty-string rejection.
  • Expression, limit and response-shape parity: KeyConditionExpression operand and nested-path rules, ExpressionAttributeNames/Values hygiene, projection validation and list-index fidelity, reversed-bounds BETWEEN, read-path key-length and segment caps, whitespace numbers, batch unprocessed fields and cross-table projection mixing, the bare no-op upsert, multi-subpath UPDATED_NEW, filter operand ordering, hash-only-GSI pagination, and CreateTable spec validation.
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Suite on

Grew to 824 tests, up 7, in two parts: two sibling-parity gaps where one half of a rule was pinned and the other was not, and the capacity accounting of conditional and idempotent transactional writes. All characterised against real DynamoDB in eu-west-2.

The first covers the LSI side of the INCLUDE-projection-without-NonKeyAttributes rejection; the GSI side already had it. An LSI declared with ProjectionType INCLUDE and no NonKeyAttributes is rejected as a ValidationException in tier1 and pinned to the exact message in tier3, the same wording the GSI case returns.

The second pins the Query message for Select SPECIFIC_ATTRIBUTES with no ProjectionExpression, which Scan already had. Query and Scan enforce the same rule but word it differently: Query wraps the phrase in the "1 validation error detected:" envelope, Scan returns it bare.

The transaction cases settle what a conditional TransactWriteItems actually costs. A passing condition adds no read capacity: a conditional write bills the same 2 WCU per sub-1KB item as an unconditional one, and a standalone ConditionCheck costs 2 WCU, billed as write not read. Idempotent replay splits the accounting - the first call reports 2 write capacity units, a same-token replay within the window reports 2 read capacity units for re-reading the stored result. A failing condition cancels the transaction, and the response carries no ConsumedCapacity at all. Answers #27.

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Suite on

Grew to 762 tests, up 18, covering a malformed value in the lookup Key of a TransactWriteItems Update, Delete, or ConditionCheck - the path a Put item key does not take. Captured across four regions (eu-west-2, us-east-1, ap-southeast-2, eu-central-1), where every string was identical, so they pin exactly. An empty-string Key surfaces as a top-level ValidationException with the same message a Put item key gives; a wrong-typed or non-scalar Key cancels with a ValidationError reason carrying "The provided key element does not match the schema" - the key-only form, not the "Type mismatch for key" message the item-key path returns. The same run confirmed the BatchWriteItem table-key schema-mismatch message is region-invariant.

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Suite on

Grew to 744 tests, up 8, pinning the Select / ProjectionExpression rules on Query and Scan. A ProjectionExpression is only valid with Select SPECIFIC_ATTRIBUTES, and ALL_PROJECTED_ATTRIBUTES is only valid with an IndexName; real DynamoDB rejects both with a ValidationException before reading anything. The cases span ALL_ATTRIBUTES, COUNT, and ALL_PROJECTED_ATTRIBUTES, including the request that breaks both rules at once, where AWS reports the ProjectionExpression one. They assert the contractual phrase, so they hold whether or not the engine carries the wrapper AWS adds on Query but not Scan.

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Suite on

Grew to 736 tests, up 30, covering what TransactWriteItems and BatchWriteItem do with an item whose key value is malformed - the wrong type, non-scalar, or an empty string - across both table and index keys. PutItem already covered this; the transactional and batch paths covered none of it.

Characterising it against real AWS turned up a split worth pinning. An empty-string key value is rejected by up-front input validation, so even inside a transaction it surfaces as a top-level ValidationException. A wrong-typed or non-scalar key value is caught while the transaction runs, so it comes back as a TransactionCanceledException carrying a ValidationError reason rather than a top-level error. BatchWriteItem has no cancellation path, so every variant there is a plain ValidationException. The tests pin both halves, which catches two opposite mistakes: an engine that wraps the empty-string case as a cancellation, and one that surfaces the type-mismatch case as a top-level error.

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Suite on

Grew to 706 tests, up 7, tightening secondary-index behaviour in Tier 1. Query and Scan on a GSI or LSI now assert sparse membership: an item that omits the index key stays off the index but remains on the base table. And PutItem now rejects an item whose GSI or LSI key value is the wrong type, non-scalar, or an empty string while the base-table keys are valid, holding an index key to its declared scalar type the same way a table key is held.

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Suite on

Real DynamoDB in eu-west-2 reworded a chunk of its validation errors, and the Tier 3 error-message tests moved with it. They now assert the contract the error carries - its type, the field it objects to, and the constraint - rather than the exact prose, because AWS varies the wrapper, the echoed input value and the field casing from one region to the next. A four-region capture in June found eu-west-2 and eu-central-1 on the new wording and us-east-1 and ap-southeast-2 still on the old, so the line between contract and cosmetic is drawn from what is invariant across all four.

This moves some Tier 3 numbers. Targets that were only ever marked down for wording DynamoDB itself renders inconsistently now pass those checks, so their Tier 3 scores rise: the suite has stopped counting a cosmetic difference as a behavioural one. Genuine behavioural divergences are still pinned exactly, for example PutItem with a { NULL: false } attribute, which DynamoDB now accepts in eu-west-2 and normalises to { NULL: true }.

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Suite on

Grew to 684 tests with a control-plane and table-configuration sweep: the CreateTable/UpdateTable config parameters and the secondary control-plane operations (limits, backups and PITR, exports and imports, Kinesis, resource policies, contributor insights), each characterised against real AWS and probe-skipped where a target doesn't implement it.

The published percentage changed with it. It now measures correctness over implemented operations, Pass / (Pass + Fail), so skips no longer count against the score. A skip is honest scope; a fail is a bug.

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Suite on

Grew to 625 tests, up 24 on the previous run: eleven more in Tier 1 and thirteen more in Tier 3, tightening coverage of core operations and the strict edge cases.

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Suite on

ExtendDB joined the run as a target. The suite itself held steady at 601 tests.

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Suite on

Grew to 601 tests, up 29, and every new test landed in Tier 3: a broader strict surface spanning validation ordering, exact error messages, service limits, and the legacy request shapes. Floci and Ministack were added to the run as targets the same day.

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Grew to 572 tests, up 46 on the first run: thirty-six more in Tier 1 and ten more in Tier 2, deepening coverage of the core and complete-feature behaviour.

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Suite on

The suite was established with 526 tests across the three tiers (267 Tier 1, 93 Tier 2, 166 Tier 3), run against Dynalite, DynamoDB Local, Dynoxide, and LocalStack, with live AWS DynamoDB as the baseline.

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