@Marlin Mixon 
 It is just not possible the way you tried. Because: (from class docs)

Move to this position in the stream. If this suceeds then return true, else return false. Note this implementation is not efficient because it searches from the start of the stream,

This means it does a Rewind() and a Read(position) 

• method Write(data As %RawString) as %Status

Appends the string data to the stream and advances the current stream position by the number of characters in data.

Note that a write operation immediately following a read or rewind will clear out the existing data in the stream.

%SYS>d ^SECURITY
  
1) User setup
2) Role setup
3) Service setup
4) Resource setup
5) Application setup
6) Auditing setup
8) SSL configuration setup
9) Mobile phone service provider setup
10) OpenAM Identity Services setup
11) Encryption key setup
12) System parameter setup
13) X509 User setup
14) KMIP server setup
15) Exit
 
Option? 1
 
1) Create user
2) Edit user
3) List users
4) Detailed list users
5) Delete user
6) Export users
7) Import users
8) Exit
 
Option?

so you can call the local  commandline ( session  or terminal) and run
your SELECT in SQL shell [  do $system.SQL.Shell() ]
or from SMP System->Explorer->SQL  to see if there is any content.

If there is some content you may try next to use variables from the global scope
for your  embeded SQL
instead of 
&sql(Select demoVersion into :DemoVersion from demointerface.DemoInstances where ID=:demoID)

try it with
&sql(Select demoVersion into :%DemoVersion from demointerface.DemoInstances where ID=:%demoID)

The VIEW as such could be understood as a complex SELECT which definition is stored in the system 
At the first time processing, all code for access is generated and cached in the system
and marked with a signature. this may take a few seconds.
In parallel, a significant amount of structural data are also cached

The next time you call it, the signature is calculated and the already cached code is executed. 
You save time for code generation and compilation.
If this happens shortly after the first call you take additional advantage of the cached structural data.
How much and how long structural data are caches depends on the available buffer pool

Hi @Jack Huser,
I assume you would agree it is fair to compare apples to apples
but not horse coaches to formula-1 cars.


Being proud that I never lost a benchmark by speed I rewrote your code
that is nice to read and maintain but not very efficient, going for something
more speedy to show the limits and then checked it against your class.
My test file has only 47MB containing 181566 lines.

DEMO>write ##class(JUH.Test).ReadFile(file)
execution: 214.931024
1
DEMO>write ##class(JUH.Test).ReadQuick(file)
execution: .753696
lines: 181566
1
DEMO>write .753696/214.931024*100_" %"
.3506687801385062028 %

I think 0.35% is quite an eye catcher.

And his is the class:

 ClassMethod ReadQuick(strINReadFile As %String = "") As %Status
 {
  open strINReadFile::1 
  else  write "Missing File",! quit '$$$OK 
  set eof=##class(%SYSTEM.Process).SetZEOF(1)
  use strINReadFile
  set time1=$zh 
  for line=0:1 {
    read strBuffer if $zeof set diff=$zh-time1 quit
    // do something with strBuffer
  }
  close strINReadFile
  do ##class(%SYSTEM.Process).SetZEOF(eof)
  write !,"execution: "_diff,!,"lines: ",line,!
  quit $$$OK
 }

I just couldn't resist my nature.

I did further investigations on 'broken' input files and placed a related issue
https://github.com/MakarovS96/cache-tort-git/issues/8
It happened a little bit by accident but I found this a possible realistic scenario that explains
why the problem occurs every now and then.  You may argue this is bad handling by user.
Accepted. But not unlikely.

I found this situation:

  • I have a project. with several packages and classes
  • I deleted a class BUT the PACKAGE was not saved and didn't reflect the change
  • From ClassMethod ExportProject(project ,1) I get this strange XML for the deleted class c:\temp\TEST\dc\MyCompany\EmployeRegister1.cls.xml <?xml version="1.0" encoding="UTF-8"?> <Export generator="IRIS" version="26"> </Export>
  • now I need a GIT expert to analyze what happens with this incomplete input.
  • my assumption: according to the file name there is an empty entry of type CLS named /dc/MyCompany/EmployeRegister1.cls.xml or similar
  • when ist is restored it may cause the described problem togehter with the reported bug in $system.OBJ.Load() 

Finally, the docker image now builds OK and contains all required classes & all globals.
( + also the bug in dc.script.Genre.cls was fixed) 
Connection to local PowerBi now works and shows the expected images.
Thanks for fixing it.

I was somewhat surprised that IRIS Analytics was not required at all since there
was no Cube nor Pivot nor Dashboard. I built it myself just using dc.dc.bi.PopSongs.

OK. PowerBI graphics look better.
But here is not the place to comment on ZEN graphics.