Hi @Lucas Fernandes 

It was a little bit more complicated than expected. Anyhow take a look
SQL for ^ERROR Global

Thanks to @José Roberto Pereira  for the inspiration.

in IRIS if the data type is any numeric (%Integer, %Decimal, %Float, ..... or %Boolean)  the value is NOT enclosed in  Quotes.

Just to outline my understanding:
my package will be rcc.subject.classname   
rarely eventually zrcc.subject.classname  if it should go to %SYS .

And I will not touch/ rename existing projects as this means changing not just the code
but also README.md , Descriptions in OEX and Articles in DC, Screenshots, Dependencies (not just my own), ...
Over all a good source for mistakes, typos, errrors, confusion, 

What is the rule for VERSION  in Dependencies ?
Is it an EQUAL or a MINIMUM Version.   

e.g. <Version>0.0.0</Version>  would mean any version 

<Dependencies>
        <ModuleReference>
          <Name>holefoods</Name>
          <Version>0.1.0</Version>
        </ModuleReference>
      </Dependencies>

Thanks ! 

The so-called SQLformat doesn't exist in Caché (at least not in the last 20 years)
But over the gateway, you can move data from Caché to PostgeSQL.  "from a table on CACHE  to a POSTGRESQL table"

So you need a trigger to do it:
- Caché has to be the active part here
you can start the upload over a webservice, an REST call, even as an SQLprocedure, or automatically by the scheduler
And if you don't want to touch your target table directly you may have a shadow-copy in PostgreSQL that
then serves as a source for your final updates.  ( some INSERT...SELECT....)

So instead of import from CSV, you do an import from a local table in PostgreSQL
Anything is better than CSV.
This would even allow filling your shadow over the day in small steps instead of a big bang (if needed)

a little bit cross thinking it reminds me of this
 https://community.intersystems.com/post/unlimited-unique-index

I 've never seen the 1000 cols limit. (Consider the record size and the related impact to storage !)

But in a comparable situation, I used an array with the column name as a key.  => unlimited columns, slim storage.
And you can work on it in SQL and in classes.
BUT this is object thinking, not straight SQL 

Great stuff @Vitaliy.Serdtsev 
https://docs.intersystems.com/iris20192/csp/docbook/Doc.View.cls?KEY=RSQL_json

everlasting learning! 

Got you! 
Something  like $isJSON()  ?  like $isobject() or $listvalid()