Are multiple SPARL update queries in same POST message one transaction?

Dear Rakesh,

yes, they are executed as one transaction and satisfy the transaction isolation guarantees documented in https://docs.aws.amazon.com/neptune/latest/userguide/transactions-neptune.html; as such, all update statements in the POST message are guaranteed to either succeed as an atomic unit or fail (in the latter case, partial changes would be rolled back internally).

Best,
Michael