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| <!DOCTYPE concept PUBLIC "-//OASIS//DTD DITA Concept//EN" "concept.dtd"> |
| <concept id="compute_stats_sample_min_sample_size" rev="2.12.0"> |
| <title>COMPUTE_STATS_MIN_SAMPLE_SIZE Query Option</title> |
| <titlealts audience="PDF"> |
| <navtitle>COMPUTE_STATS_MIN_SAMPLE_SIZE</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>The <codeph>COMPUTE_STATS_MIN_SAMPLE_SIZE</codeph> query option specifies |
| the minimum number of bytes that will be scanned in <codeph>COMPUTE STATS |
| TABLESAMPLE</codeph>, regardless of the user-supplied sampling percent. |
| This query option prevents sampling for very small tables where accurate |
| stats can be obtained cheaply without sampling because the minimum sample |
| size is required to get meaningful stats.</p> |
| <p conref="../shared/impala_common.xml#common/type_integer"/> |
| <p><b>Default:</b> 1GB</p> |
| <p><b>Added in</b>: <keyword keyref="impala212_full"/></p> |
| <p conref="../shared/impala_common.xml#common/usage_notes_blurb"/> |
| </conbody> |
| </concept> |