Method two_phase_transactions

test/requirements.py:972–1014

Target database must support two-phase transactions.

(self)

    @property
    def two_phase_transactions(self):
        """Target database must support two-phase transactions."""

        def pg_prepared_transaction(config):
            if not against(config, "postgresql"):
                return True

            with config.db.connect() as conn:
                try:
                    num = conn.scalar(
                        text(
                            "select cast(setting AS integer) from pg_settings "
                            "where name = 'max_prepared_transactions'"
                        )
                    )
                except exc.OperationalError:
                    return False
                else:
                    return num > 0

        return skip_if(
            [
                no_support("mssql", "two-phase xact not supported by drivers"),
                no_support(
                    "sqlite", "two-phase xact not supported by database"
                ),
                no_support("oracle+cx_oracle", "prefer oracledb"),
                # in Ia3cbbf56d4882fcc7980f90519412f1711fae74d
                # we are evaluating which modern MySQL / MariaDB versions
                # can handle two-phase testing without too many problems
                # no_support(
                #     "mysql",
                #    "recent MySQL community editions have too many "
                #    "issues (late 2016), disabling for now",
                # ),
                NotPredicate(
                    LambdaPredicate(
                        pg_prepared_transaction,
                        "max_prepared_transactions not available or zero",
                    )
                ),
            ]
        )

    @property
    def two_phase_recovery(self):