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Re: String Representation of DataBag and its Schema
By hand; creating a new JUnit method to test a specific use case against a
functional requirement in the UDF.

The UDFs I am testing are part of a larger ETL testing initiative I have
been undertaking.  To ensure that the various states of legacy data are
correctly extracted and transformed into a Pig context, I am creating
specific JUnit tests per each UDF containing specific use cases as testing
methods.

Motivation to use String inputs for the Data Objects and Schema Objects is
the improvement on the conventional approach - creating Java Objects and
adding and appending nested Objects to create the desired complex type
DataBag Object to pass to the UDF as use case input. This simpler process
I'm looking for should improve scale-ability and rapid-prototyping within
the testing scripts.  It will also make the process more approachable for
another programmer to write additional unit tests.

-Dan

On Tue, Mar 19, 2013 at 11:43 AM, Jonathan Coveney <[EMAIL PROTECTED]>wrote:

> How are you planning on generating these cases? By hand? Or automated?
>
>
> 2013/3/19 Dan DeCapria, CivicScience <[EMAIL PROTECTED]>
>
> > String string_databag in this example was typed out by me, as the input
> > String for a JUnit test method. I am considering generating many of these
> > for case specific unit testing of my UDFs.
> >
> > -Dan
> >
> > On Tue, Mar 19, 2013 at 11:27 AM, Jonathan Coveney <[EMAIL PROTECTED]
> > >wrote:
> >
> > > how was string_databag generated?
> > >
> > >
> > > 2013/3/19 Dan DeCapria, CivicScience <[EMAIL PROTECTED]>
> > >
> > > > Expanding upon this, the following use case's Schema Object can be
> > > resolved
> > > > from inputs:
> > > >
> > > >         String string_databag = "{(a,(b,d),f)}";
> > > >         String string_schema > > > > "b1:bag{t1:tuple(a:chararray,t2:tuple(b:chararray,d:long),f:long)}";
> > > >         Schema schema = Utils.getSchemaFromString(string_schema);
> > > >
> > > > Next step is to resolve a DataBag Object from String string_databag
> and
> > > the
> > > > Schema Object.
> > > >
> > > > -Dan
> > > >
> > > > On Tue, Mar 19, 2013 at 9:37 AM, Dan DeCapria, CivicScience <
> > > > [EMAIL PROTECTED]> wrote:
> > > >
> > > > > Thank you for your reply.
> > > > >
> > > > > The problem is I cannot find a methodology to go from a String
> > > > > representation of a complex data type to a nested Object of pig
> > > > DataTypes.
> > > > > I looked over the pig 0.10.1 docs, but cannot find a way to go from
> > > > String
> > > > > and Schema to pig DataType Object.
> > > > >
> > > > > For context, I am generating these Strings for my own JUnit testing
> > of
> > > > > other UDFs.  Currently, for complex types, I have to generate each
> > > > nesting
> > > > > from Tuple and DataBag factories, append data, and next them
> > manually.
> > > >  For
> > > > > larger unit tests, this process becomes unwieldy (hundreds of lines
> > per
> > > > > method, non-dynamic), and it would be much simpler to go directly
> > from
> > > a
> > > > > String and a Schema to a DataBag Object for UDF testing (few lines
> of
> > > > code,
> > > > > easily modifiable).
> > > > >
> > > > > -Dan
> > > > >
> > > > >
> > > > > On Mon, Mar 18, 2013 at 6:31 PM, Jonathan Coveney <
> > [EMAIL PROTECTED]
> > > > >wrote:
> > > > >
> > > > >> Why not just use PigStorage? This is essentially what it does. It
> > > saves
> > > > a
> > > > >> bag as text, and then loads it again.
> > > > >>
> > > > >> I suppose the question becomes: why do you need to do this?
> > > > >>
> > > > >>
> > > > >> 2013/3/18 Dan DeCapria, CivicScience <
> [EMAIL PROTECTED]
> > >
> > > > >>
> > > > >> > In Java, I am trying to convert a DataBag from it's String
> > > > >> representation
> > > > >> > with its schema String to a valid DataBag Object:
> > > > >> >
> > > > >> > String databag_string = "{(apples,1024)}";
> > > > >> > String schema_string = "b1:bag{t1:tuple(a:chararray,b:long)}";
> > > > >> >
> > > > >> > I've tried implementing something along the lines of this, but I

Dan DeCapria
CivicScience, Inc.
Senior Informatics / DM / ML / BI Specialist