Good luck, bro. :) May i ask why are you doing this to yourself? I think your instincts are correct going down the path you describe sounds a tad more painful than just hitting yourself in the head with a hammer. Different strokes for different folks though.
so can we back up? what - briefly if possible - do you want to achieve with a "wrapper"? (i'm going to regret asking that i know.) On Tue, Jun 25, 2013 at 7:29 AM, Peter Marron < peter.mar...@trilliumsoftware.com> wrote: > Hi,**** > > ** ** > > Running Hive 0.11.0 over Hadoop 1.0.4.**** > > ** ** > > I would like to be able to “wrap” a Hive table.**** > > ** ** > > So, if I have table “X” which uses SerDe “s” and InputFormat “i”**** > > then I would like to be able to create a table “Y” which has a **** > > SerDe “ws” which is a wrapper of “s” (and so can encapsulate an instance > of “s”)**** > > and an InputFormat “wi” which is a wrapper of “I” (and similarly > encapsulates an**** > > instance of “i”). So far I have done this by creating a table like this** > ** > > ** ** > > CREATE TABLE Y (… copy of underlying table’s columns...)**** > > ROW FORMAT SERDE 'ws'**** > > WITH SERDEPROPERTIES (…**** > > 'wrapped.serde.name'='org.apache.hadoop.hive.serde2.lazy.LazySimpleSerDe', > **** > > ‘wrapped.inputformat.name’=’TextInputFormat’,**** > > 'serialization.format'='|', 'field.delim'='|'**** > > )**** > > STORED AS**** > > INPUTFORMAT 'wi'**** > > OUTPUTFORMAT 'org.apache.hadoop.hive.ql.io.HiveIgnoreKeyTextOutputFormat' > **** > > TBLPROPERTIES (…);**** > > ** ** > > I have to add the names of the underlying classes “s” and “I”**** > > into the table properties so that I know what to instantiate.**** > > I also have to replicate all the column details of the wrapped table**** > > to ensure the correct information is passed down to the underlying SerDe** > ** > > when I instantiate it. I also have to know the output format. I have to*** > * > > explicitly add the default SerDe properties to get it to work.**** > > I have to explicitly provide the default output format too.**** > > If any changes are made to the underlying table then I need to reflect**** > > those changes in my “wrapper” table.**** > > It’s a mess.**** > > ** ** > > What I’d like to be able to do is to just parameterise my wrapper**** > > table with the name of the underlying table and using that name**** > > be able to instantiate the correct SerDe and InputFormat.**** > > ** ** > > Is there an easier way to do this?**** > > ** ** > > Any pointers appreciated.**** > > ** ** > > Z**** > > ** ** >
