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From "Scott Lewis (JIRA)" <j...@apache.org>
Subject [jira] [Updated] (DERBY-5466) Add support for SQL Standard statistics functions, such as STDDEV_POP, STDDEV_SAMP, VAR_POP, VAR_SAMP
Date Mon, 03 Aug 2015 17:07:04 GMT

     [ https://issues.apache.org/jira/browse/DERBY-5466?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
]

Scott Lewis updated DERBY-5466:
-------------------------------
    Attachment: DERBY-5466.stats.patch

Attached is first patch including four new aggregate functions implementing VarP, VarS, StdDevP,
and StdDevS statistics functions.   In my local environment I've been able to build and test
them with a small database/table.  

I'm attaching them here for initial review, and will likely need some guidance as to how to
write test code for them in the derby test suite, assuming that's going to be needed at some
point.

Thanks.




> Add support for SQL Standard statistics functions, such as STDDEV_POP, STDDEV_SAMP, VAR_POP,
VAR_SAMP
> -----------------------------------------------------------------------------------------------------
>
>                 Key: DERBY-5466
>                 URL: https://issues.apache.org/jira/browse/DERBY-5466
>             Project: Derby
>          Issue Type: Improvement
>          Components: SQL
>    Affects Versions: 10.8.1.2
>            Reporter: Lukas Eder
>            Priority: Minor
>              Labels: derby_triage10_10
>         Attachments: DERBY-5466.stats.patch
>
>
> Any of these RDBMS support the SQL standard statistics functions STDDEV_POP, STDDEV_SAMP,
VAR_POP, VAR_SAMP:
> - DB2 (only STDDEV, VARIANE)
> - H2 
> - HSQLDB 
> - Ingres 
> - MySQL 
> - Oracle 
> - Postgres 
> - SQL Server (named STDEVP, STDEV, VARP, VAR)
> - Sybase ASE
> - Sybase SQL Anywhere
> These don't:
> - Derby
> - SQLite
> This would be a useful addition for Derby, I think.
> An even larger example list of possible statistics aggregate functions is listed in the
Postgres documentation:
> http://www.postgresql.org/docs/9.0/static/functions-aggregate.html#FUNCTIONS-AGGREGATE-STATISTICS-TABLE



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