Jesus Camacho Rodriguez created HIVE-22239:
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Summary: Scale data size using column value ranges
Key: HIVE-22239
URL: https://issues.apache.org/jira/browse/HIVE-22239
Project: Hive
Issue Type: Improvement
Components: Physical Optimizer
Reporter: Jesus Camacho Rodriguez
Assignee: Jesus Camacho Rodriguez
Currently, min/max values for columns are only used to determine whether a
certain range filter falls out of range and thus filters all rows or none at
all. If it does not, we just use a heuristic that the condition will filter 1/3
of the input rows. Instead of using that heuristic, we can use another one that
assumes that data will be uniformly distributed across that range, and
calculate the selectivity for the condition accordingly.
This patch also includes the propagation of min/max column values from
statistics to the optimizer for timestamp type.
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