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.
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: