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<!DOCTYPE concept PUBLIC "-//OASIS//DTD DITA Concept//EN" "concept.dtd">
<concept rev="3.2.0" id="resource_trace_ratio">
<title>RESOURCE_TRACE_RATIO Query Option (<keyword keyref="impala32_full"/> or higher only)</title>
<titlealts audience="PDF">
<data name="Category" value="Impala"/>
<data name="Category" value="Impala Query Options"/>
<data name="Category" value="Querying"/>
<data name="Category" value="Developers"/>
<data name="Category" value="Data Analysts"/>
The <codeph>RESOURCE_TRACE_RATIO</codeph> query option specifies the ratio of queries
where the CPU usage info will be included in the profiles. Collecting CPU usage and
sending it around adds a slight overhead during query execution. This query option lets
you control whether to collect additional information to diagnose the resource usage.
For example, setting <codeph>RESOURCE_TRACE_RATIO=1</codeph> adds a trace of the CPU usage
to the profile of each query.
Setting <codeph>RESOURCE_TRACE_RATIO=0.5</codeph> means that randomly selected half of all
queries will have that information collected by the coordinator and included in the
Setting <codeph>RESOURCE_TRACE_RATIO=0</codeph> means that CPU usage will not be tracked
and included in the profiles.
Values from 0 to 1 are allowed.
<b>Type:</b> Number
<b>Default:</b> 0
<b>Added in:</b> <keyword keyref="impala32"/>