Function commit_failed 

pub fn commit_failed(error: &Error) -> StoreError

Maps the failure of a COMMIT statement.

A commit that does not answer is the one place where this adapter cannot say whether the write landed, so it reports StoreError::Timeout: the caller must re-read rather than retry (spec §16.5). A commit refused by the server with a SQLSTATE — a deferred constraint, a serialization failure — did roll back and keeps its normal classification.