Has anyone tried to install cache on an external flash drive?

My new question regards connecting to the external database to insert the data. I have the following code:

#include %occInclude
// winsurge6
// insert winsurge data into cancer registry database
// Create new Gateway connection object
set gc=##class(%SQLGatewayConnection).%New()
If gc=$$$NULLOREF quit $$$ERROR($$$GeneralError,"Cannot create %SQLGatewayConnection.")
//Make connection to target DSN
s pDSN="CGDEV"
s usr="WINSURGE_DMP"
s pwd="xxxxxxxx"
s sc=gc.Connect(pDSN,usr,pwd,0)
If $$$ISERR(sc) quit sc
if gc.

I am tasked with using CACHE to insert data retrieved from a CACHE data base and insert it into an sql database. The columns in the sql table that I am trying to insert data into have names that contain underscores such as "ACCESSION_DATE" I found a utility in CACHE to connect to the sql data base and perform inserts. I have the data I need to insert. I need to pass the  data into the sql utility referencing the column names.

I tried using indirection to set the data into underscored variables, but that isn't allowed  in cache object script.

Anyone have suggestions as to how to do that?

I'm trying to learn how To use SQL in CACHE, so I hope I don't bore you with "Dumb" questions.... 

I'm getting "ERROR #6022: Gateway failed" message following this line of code. 

s sc=gc.Prepare(hstmt,pQuery) 

This line of code comes from an example I found in the documentation.  pQuery is the "Select" statement setting up the variables and tables I'm trying to pull information from. 

What does that error indicate? 

Thank you. 

I'm trying to create an sal connections from one cache system to another. I've created the connection part  and I think that is working. When trying to link a table through the link table wizard, I'm getting an error "<MAXSTRING>zCreateOneLinkTable+52^%CSP.UI.SQL.LinkWizardResultPage1.

Is this due to my global block size in the new system not being large enough? It is currently set at 8192.

Thank you

Mike