def METHOD_NAME():
    bind = op.get_bind()
    insp = engine.reflection.Inspector.from_engine(bind)
    # Remove the missing uniqueness constraint from the sql_metrics table.
    with op.batch_alter_table("sql_metrics", naming_convention=conv) as batch_op:
        batch_op.drop_constraint(
            generic_find_uq_constraint_name(
                "sql_metrics", {"metric_name", "table_id"}, insp
            )
            or "uq_sql_metrics_table_id",
            type_="unique",
        )
    # Restore the size of the sql_metrics.metric_name column and forego that it
    # be non-nullable.
    with op.batch_alter_table("sql_metrics") as batch_op:
        batch_op.alter_column(
            "metric_name", existing_type=String(255), nullable=True, type_=String(512)
        )
    # Forego that the sql_metrics.expression column be non-nullable.
    with op.batch_alter_table("sql_metrics") as batch_op:
        batch_op.alter_column("expression", existing_type=Text, nullable=True)
    # Forego that the metrics.metric_name column be non-nullable.
    with op.batch_alter_table("metrics") as batch_op:
        batch_op.alter_column("metric_name", existing_type=String(255), nullable=True)
    # Forego that the metrics.json column be non-nullable.
    with op.batch_alter_table("metrics") as batch_op:
        batch_op.alter_column("json", existing_type=Text, nullable=True)