Fucun Chu created IMPALA-10718:
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Summary: Implement ds_tuple_arrayofdouble_sketch() and
ds_tuple_arrayofdouble_estimate() functions
Key: IMPALA-10718
URL: https://issues.apache.org/jira/browse/IMPALA-10718
Project: IMPALA
Issue Type: New Feature
Components: Backend, Frontend
Reporter: Fucun Chu
Assignee: Fucun Chu
These should be built-in functions that use DataSketches functionality that was
integrated by [IMPALA-10717|https://issues.apache.org/jira/browse/IMPALA-10717].
ds_tuple_arrayofdouble_sketch() should receive a primitive expression,
parameter and return a sketch.
ds_tuple_arrayofdouble_estimate() should receive a sketch and return a
primitive that is the cardinality estimate for that set of data provided to the
sketch.
Usage:
{code:java}
select ds_tuple_arrayofdouble_estimate(ds_tuple_arrayofdouble_sketch(col_name,
parameter)) from table_name;
{code}
Returns a cardinality estimate for that particular column.
Hive change that introduced the same:
https://issues.apache.org/jira/browse/HIVE-22940
https://github.com/apache/hive/blob/master/ql/src/java/org/apache/hadoop/hive/ql/exec/DataSketchesFunctions.java
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