AWS, Dynamodb, Database, Distributed Systems, NoSQL.
Expression.builder() .expression("completionStatus = :cs") .expressionValues(Map.of(":cs", AttributeValue.fromS("IN_PROGRESS"))) .build()) .returnValuesOnConditionCheckFailure("ALL_OLD") .item(idempotencyRecord) .build()); In brief, if two Lambda instances are executed concurrently with the same