RUNTIME_FILTER_WAIT_TIME_MS Query Option (Impala 2.5 or higher only)

The RUNTIME_FILTER_WAIT_TIME_MS query option adjusts the settings for the runtime filtering feature. It specifies a time in milliseconds that each scan node waits for runtime filters to be produced by other plan fragments. Note that the wait time for a runtime filter is with respect to the start of processing the query in the given executor instead of the beginning of the Open phase of a scan node. For instance, a scan node could start so late that at the beginning of the Open phase of the scan node, the amount of time passed since the start of query processing was already greater than the value of RUNTIME_FILTER_WAIT_TIME_MS. In such a case, even though the runtime filter has not arrived yet, the scan node will not wait any longer.

Type: integer

Default: 0 (meaning use the value from the corresponding impalad startup option)

Added in: Impala 2.5.0

Usage notes:

Because the runtime filtering feature applies mainly to resource-intensive and long-running queries, only adjust this query option when tuning long-running queries involving some combination of large partitioned tables and joins involving large tables.

Related information:

Runtime Filtering for Impala Queries (Impala 2.5 or higher only), RUNTIME_FILTER_MODE Query Option (Impala 2.5 or higher only)