Gabor Kaszab created IMPALA-9959:
------------------------------------
Summary: Implement ds_kll_sketch() and ds_kll_quantile() functions
Key: IMPALA-9959
URL: https://issues.apache.org/jira/browse/IMPALA-9959
Project: IMPALA
Issue Type: Improvement
Components: Backend, Frontend
Reporter: Gabor Kaszab
1:
STRING ds_kll_sketch(float)
Accepts float as parameter and returns a DataSketches KLL sketch in string
type (or binary once that work is submitted).
2:
FLOAT (or DOUBLE?) ds_kll_quantile(KLL sketch, double)
Accepts two parameters: a KLL sketch created by ds_hll_sketch() and a double
in [0, 1] to represent the quantile.
At this point I'm not sure about the return value, it's either a float or
double, it's a subject of further investigation.
Example:
{code:java}
select ds_kll_quantile(ds_kll_sketch(cast(int_col as float)), 1) from
table_name;
+------+
| _c0 |
+------+
| 1.0 |
+------+
{code}
Some further examples found here:
[https://datasketches.apache.org/docs/Quantiles/QuantilesCppExample.html]
--
This message was sent by Atlassian Jira
(v8.3.4#803005)
---------------------------------------------------------------------
To unsubscribe, e-mail: [email protected]
For additional commands, e-mail: [email protected]
