blob: ee5136d87388436680ff75c224fcb09538015bf0 [file] [log] [blame]
<?xml version="1.0" encoding="UTF-8"?>
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<!DOCTYPE concept PUBLIC "-//OASIS//DTD DITA Concept//EN" "concept.dtd">
<concept id="max_mem_estimate_for_admission">
<title>MAX_MEM_ESTIMATE_FOR_ADMISSION Query Option</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"/>
Use the <codeph>MAX_MEM_ESTIMATE_FOR_ADMISSION</codeph> query option to set an upper limit
on the memory estimates of a query as a workaround for over-estimates precluding a query
from being admitted.
The query option takes effect when all of the below conditions are met:
Memory-based admission control is enabled for the pool.
The <codeph>MEM_LIMIT</codeph> query option is not set at the query, session, resource
pool, or global level.
When the above conditions are met, MIN(<codeph>MAX_MEM_ESTIMATE_FOR_ADMISSION</codeph>,
mem_estimate) is used for admission control.
Setting the <codeph>MEM_LIMIT</codeph> query option is usually a better option. Use the
<codeph>MAX_MEM_ESTIMATE_FOR_ADMISSION</codeph> query option when it is not feasible to
set <codeph>MEM_LIMIT</codeph> for each individual query.
<p conref="../shared/impala_common.xml#common/type_integer"/>
<p conref="../shared/impala_common.xml#common/default_blurb"/>
<b>Added in:</b> <keyword keyref="impala31"/>
<p conref="../shared/impala_common.xml#common/usage_notes_blurb"/>
<p conref="../shared/impala_common.xml#common/related_info"/>