[HIVE-16178] corr/covar_samp UDAF standard compliance

• Type: Sub-task
• Status: Resolved
• Priority: Minor
• Resolution: Fixed
• Fix Version/s: 2.3.0
• Component/s: SQL
• Labels: TODOC2.2
• Assignee: Zoltan Haindrich
• Reporter: Zoltan Haindrich
• Created: 10/Mar/17 23:12
• Updated: 21/Jul/17 18:46
• Resolved: 21/Mar/17 17:10

Description

corr

the standard defines corner cases when it should return null - but the current result is NaN.

If N * SUMX2 equals SUMX * SUMX , then the result is the null value.
and
If N * SUMY2 equals SUMY * SUMY , then the result is the null value.

covar_samp

returns 0 instead 1

`If N is 1 (one), then the result is the null value.`

check (x,y) vs (y,x) args in docs

the standard uses (y,x) order; and some of the function names are also contain X and Y...so the order does matter..currently at least corr uses (x,y) order which is okay - because its symmetric; but it would be great to have the same order everywhere (check others)

Issue Links

• relates to: HIVE-15978 Support regr_* functions