Before revision:  However, existing tools for querying, analyzing , and exploring data in cloud warehouses are either limited in facilitating iterative ad-hoc analysis or difficult to use for the largest segment of enterprise users, who have limited time, interest, or skills for writing queries .
After revision:  However, existing tools for querying, analyzing , and exploring data in cloud warehouses are either limited in facilitating iterative ad-hoc transformations or difficult to use for the largest segment of enterprise users, who have limited time, interest, or skills for writing queries .