Techniques are described for managing query execution by estimating and monitoring query execution time. Embodiments of the invention may generally receive a query to be executed and calculate an initial estimated execution time for the received query. If the initial estimated execution time does not exceed a threshold amount of time, embodiments of the invention may submit the query for execution. Once execution of the query has begun, embodiments of the invention may calculate an updated estimated execution time for the executing query, and if the updated estimated execution time exceeds the threshold amount of time, may halt the execution of the query.