| <?xml version="1.0" encoding="UTF-8"?> |
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| <!DOCTYPE concept PUBLIC "-//OASIS//DTD DITA Concept//EN" "concept.dtd"> |
| <concept id="buffer_pool_limit" rev="2.10.0 IMPALA-3200"> |
| |
| <title>BUFFER_POOL_LIMIT Query Option</title> |
| <titlealts audience="PDF"><navtitle>BUFFER POOL LIMIT</navtitle></titlealts> |
| <prolog> |
| <metadata> |
| <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"/> |
| </metadata> |
| </prolog> |
| |
| <conbody> |
| |
| <p> |
| <indexterm audience="hidden">BUFFER_POOL_LIMIT query option</indexterm> |
| Defines a limit on the amount of memory that a query can allocate from the |
| internal buffer pool. The value for this limit applies to the memory on each host, |
| not the aggregate memory across the cluster. Typically not changed by users, except |
| during diagnosis of out-of-memory errors during queries. |
| </p> |
| |
| <p conref="../shared/impala_common.xml#common/type_integer"/> |
| |
| <!-- BUFFER_POOL_LIMIT: [0] --> |
| |
| <p conref="../shared/impala_common.xml#common/default_blurb"/> |
| <p> |
| The default setting for this option is the lower of 80% of the |
| <codeph>MEM_LIMIT</codeph> setting, or the <codeph>MEM_LIMIT</codeph> |
| setting minus 100 MB. |
| </p> |
| |
| <p conref="../shared/impala_common.xml#common/added_in_2100"/> |
| |
| <p conref="../shared/impala_common.xml#common/usage_notes_blurb"/> |
| <p> |
| If queries encounter out-of-memory errors, consider decreasing the |
| <codeph>BUFFER_POOL_LIMIT</codeph> setting to less than 80% of the |
| <codeph>MEM_LIMIT setting</codeph>. |
| </p> |
| |
| <p conref="../shared/impala_common.xml#common/example_blurb"/> |
| |
| <codeblock><![CDATA[ |
| -- Set an absolute value. |
| set buffer_pool_limit=8GB; |
| |
| -- Set a relative value based on the MEM_LIMIT setting. |
| set buffer_pool_limit=80%; |
| ]]> |
| </codeblock> |
| |
| <p conref="../shared/impala_common.xml#common/related_info"/> |
| <p> |
| <xref keyref="default_spillable_buffer_size"/>, |
| <xref keyref="max_row_size"/>, |
| <xref keyref="min_spillable_buffer_size"/>, |
| <xref keyref="scalability_buffer_pool"/> |
| </p> |
| |
| </conbody> |
| </concept> |