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From "pi song" <pi.so...@gmail.com>
Subject Re: Question on the LogicalPlanTester
Date Sat, 21 Jun 2008 23:19:51 GMT
Then I'll have to find a work around for the Dot framework to allow entering
"no alias" case by not touching the parser

On Sat, Jun 21, 2008 at 3:03 AM, Santhosh Srinivasan <sms@yahoo-inc.com>
wrote:

> Bags have schemas. The schema of the bag is the schema of the tuple
> inside the bag. Pi is correct when he says "...doesn't output Bag fields
> with tuples wrapped inside but Bag with schema instead"
>
> Santhosh
>
> -----Original Message-----
> From: Alan Gates [mailto:gates@yahoo-inc.com]
> Sent: Friday, June 20, 2008 9:21 AM
> To: pig-dev@incubator.apache.org
> Subject: Re: Question on the LogicalPlanTester
>
> Comments inlined.
>
> pi song wrote:
> > I came across a couple more issues:-
> >
> > 1) Currently we don't allow specifying only data type but no alias in
> > schema declaration. I work around by using "null" keyword
> >
> > null:int, null:long               null means no alias specified
> >
> > This is obviously not the right solution. We again need a discussion
> > on schema declaration for different cases:-
> >  - Specify both type and alias  (Currently supported)
> >  - Specify only alias, no type  (Currently supported)
> >  - Specify only type, no alias  (Currently not supported)
> As specified, there isn't support for giving a field's type without
> giving it an alias.  I don't know that we need to allow this.
> >
> > 2) Current cogroup implementation doesn't output Bag fields with
> > tuples wrapped inside but Bag with schema instead. This is apparently
> > inconsistent with schema definition. I don't know which one is right.
> > We've discussed about this before but didn't come up with a consensus.
>
> > BTW, a quick way to work around this would be altering(hacking) schema
>
> > loading in LogicalPlanLoader.createLOCogroup()
> Santhosh, can you comment on this?  My understanding was that bags could
>
> have schemas too, as that implied that they contained tuples with that
> schema.
> >
> > <snip>
> Alan.
>

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