EXEC_TIME_LIMIT_S Query Option (Impala 2.12 or higher only)

The EXEC_TIME_LIMIT_S query option sets a time limit on query execution. If a query is still executing when time limit expires, it is automatically canceled. The option is intended to prevent runaway queries that execute for much longer than intended.

For example, an Impala administrator could set a default value of EXEC_TIME_LIMIT_S=3600 for a resource pool to automatically kill queries that execute for longer than one hour (see Admission Control and Query Queuing for information about default query options). Then, if a user accidentally runs a large query that executes for more than one hour, it will be automatically killed after the time limit expires to free up resources. Users can override the default value per query or per session if they do not want the default EXEC_TIME_LIMIT_S value to apply to a specific query or a session.

Note:

The time limit only starts once the query is executing. Time spent planning the query, scheduling the query, or in admission control is not counted towards the execution time limit. SELECT statements are eligible for automatic cancellation until the client has fetched all result rows. DML queries are eligible for automatic cancellation until the DML statement has finished.

Syntax:

SET EXEC_TIME_LIMIT_S=seconds;

Type: numeric

Default: 0 (no time limit )

Added in: Impala 2.12

Related information:

Setting Timeout Periods for Daemons, Queries, and Sessions

Parent topic: Query Options for the SET Statement