[
https://issues.apache.org/jira/browse/CALCITE-6077?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=17780045#comment-17780045
]
Julian Hyde commented on CALCITE-6077:
--------------------------------------
Do these dialects have functions for combinations and permutations?
{quote}
p(n, r) = n! / (n - r)!
c(n, r) = n! / (r! . (n - r)!)
{quote}
These are related to factorial but are more useful because, by dividing
factorials by factorials, they tend to stay in a useful range of values.
> Add FACTORIAL functions (enabled in Hive and Spark library)
> -----------------------------------------------------------
>
> Key: CALCITE-6077
> URL: https://issues.apache.org/jira/browse/CALCITE-6077
> Project: Calcite
> Issue Type: New Feature
> Components: core
> Affects Versions: 1.35.0
> Reporter: Runkang He
> Assignee: Runkang He
> Priority: Major
>
> Add FACTORIAL functions (enabled in Hive and Spark library)
> FACTORIAL(expr): Returns the factorial of expr. expr is [0..20]. Otherwise,
> returns NULL.
> For example:
> {code:sql}
> SELECT factorial(5);
> >120
> {code}
> See more at
> [Hive|https://cwiki.apache.org/confluence/display/hive/languagemanual+udf#LanguageManualUDF-MathematicalFunctions]
> and
> [Spark|https://spark.apache.org/docs/latest/api/sql/index.html#factorial] doc.
--
This message was sent by Atlassian Jira
(v8.20.10#820010)
