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Pig >> mail # dev >> Handle NULL values in Cube dimensions


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Re: Handle NULL values in Cube dimensions
Note that the current CubeDimensions UDF does a third thing -- instead
of rebranding "nulls" as "unknown" and using null to mean "*" or "all
values", the UDF allows you to specify a custom value to stand for "*"
or "all values". That way null can be an individual valid cell value.

This is (imho) much nicer than the other options, but it does
complicate working with 3rd party tools.

Does anyone have opinions on this?

D

On Wed, Jun 6, 2012 at 2:24 PM, Prasanth J <[EMAIL PROTECTED]> wrote:
> Hello everyone
>
> I would like to bring up this discussion about the ways for handling NULL values in dimensions specified for cubing. For example, if we have a dimension color with following values
>
> red
> blue
> null
> green
>
> how do we differentiate if the null value represent rollup of all colors values or actual null value?
>
> SQL way:
> There are 2 ways in which SQL server analysis services handles null values in dimensions
> 1) Throw error when it encounters null values in dimension values
> 2) Ignore error by adding the null values to UnknownMembers. By default UnknownMembers will be named as "Unknown". The name for UnknownMembers can also be specified by the user.
>
> Do we need to handle both ways in Pig? I think the first way (throwing error) is pretty straightforward.
> For the second way (ignoring error), what is the best way to provide support for user specified name for UnknownMembers?
>
> Please share your thoughts about how we can handle this scenario for different datatypes in Pig.
>
> Thanks
> -- Prasanth
>
NEW: Monitor These Apps!
elasticsearch, apache solr, apache hbase, hadoop, redis, casssandra, amazon cloudwatch, mysql, memcached, apache kafka, apache zookeeper, apache storm, ubuntu, centOS, red hat, debian, puppet labs, java, senseiDB