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<!DOCTYPE concept PUBLIC "-//OASIS//DTD DITA Concept//EN" "concept.dtd">
<concept id="runtime_filter_mode" rev="2.5.0">
<title>RUNTIME_FILTER_MODE Query Option (<keyword keyref="impala25"/> or higher only)</title>
<titlealts audience="PDF"><navtitle>RUNTIME_FILTER_MODE</navtitle></titlealts>
<data name="Category" value="Impala"/>
<data name="Category" value="Impala Query Options"/>
<data name="Category" value="Performance"/>
<data name="Category" value="Developers"/>
<data name="Category" value="Data Analysts"/>
<p rev="2.5.0">
<indexterm audience="hidden">RUNTIME_FILTER_MODE query option</indexterm>
The <codeph>RUNTIME_FILTER_MODE</codeph> query option
adjusts the settings for the runtime filtering feature.
It turns this feature on and off, and controls how
extensively the filters are transmitted between hosts.
<b>Type:</b> numeric (0, 1, 2)
or corresponding mnemonic strings (<codeph>OFF</codeph>, <codeph>LOCAL</codeph>, <codeph>GLOBAL</codeph>).
<p rev="2.6.0">
<b>Default:</b> 2 (equivalent to <codeph>GLOBAL</codeph>); formerly was 1 / <codeph>LOCAL</codeph>, in <keyword keyref="impala25_full"/>
<p conref="../shared/impala_common.xml#common/added_in_250"/>
<p conref="../shared/impala_common.xml#common/usage_notes_blurb"/>
<p rev="2.6.0">
In <keyword keyref="impala26_full"/> and higher, the default is <codeph>GLOBAL</codeph>.
This setting is recommended for a wide variety of workloads, to provide best
performance with <q>out of the box</q> settings.
<p rev="2.6.0">
The lowest setting of <codeph>LOCAL</codeph> does a similar level of optimization
(such as partition pruning) as in earlier Impala releases.
This setting was the default in <keyword keyref="impala25_full"/>,
to allow for a period of post-upgrade testing for existing workloads.
This setting is suitable for workloads with non-performance-critical queries,
or if the coordinator node is under heavy CPU or memory pressure.
You might change the setting to <codeph>OFF</codeph> if your workload contains
many queries involving partitioned tables or joins that do not experience a performance
increase from the runtime filters feature. If the overhead of producing the runtime filters
outweighs the performance benefit for queries, you can turn the feature off entirely.
<p conref="../shared/impala_common.xml#common/related_info"/>
<xref href="impala_partitioning.xml#partitioning"/> for details about runtime filtering.
<xref href="impala_disable_row_runtime_filtering.xml#disable_row_runtime_filtering"/>,
<xref href="impala_runtime_bloom_filter_size.xml#runtime_bloom_filter_size"/>,
<xref href="impala_runtime_filter_wait_time_ms.xml#runtime_filter_wait_time_ms"/>,
<xref href="impala_max_num_runtime_filters.xml#max_num_runtime_filters"/>
for tuning options for runtime filtering.