I suggest to start from the documentation:

Introduction to Namespaces and Databases

Then come back if you have more specific questions.

Have a look to this two posts:

How to programmatically obtain a list of configured namespaces

How can I get the name of the data database in the current namespace?

In case anybody cares, I've submitted the idea of supporting 2FA in DBeaver.

Add support for two-factor authentication in DBeaver

If you think that it can be important to add something else, please let us know.

How about support for two-factor authentication? 

Now days 2FA/MFA is virtually mandatory in some environment.

What's the datatype of the HL7 message in SendMessageRespose?

I assume that the HL7 message in SendMessageRespose is a %String.

String variable contains the HL7 message, then:

    Set HL7MessageResponse=##class(EnsLib.HL7.Message).ImportFromString(String,.sc)
    ; handle sc error here
    Set DocType=##class(EnsLib.HL7.Schema).ResolveSchemaTypeToDocType(HL7MessageResponse.TypeVersion,HL7MessageResponse.Name)
    Set sc=HL7MessageResponse.PokeDocType(DocType)
    ; handle sc error here

How did you installed set up your FHIR Server?

When installed using the IRIS portal the FHIR Web Application is automatically created and configured with the following Application Roles :
%DB_HSCUSTOM
%DB_HSLIB
%DB_HSSYS
%DB_<YourNamespace>X0001R
%DB_<YourNamespace>X0001V
%HS_DB_<YourNamespace>
%HS_ImpersonateUser

From the ISCSOAP log it's evident that the the content of encodedMessage property/tag is not the encoded HL7 raw message but it was assigned with an oref (object reference, an object instance) of the osuwmc.Nutrition.OSU.CBOARDNetMenuRequest.SendMessageRequest class.

This is not what the code you posted is doing, so I guess the actual code is different or the encodedMessage property is set to an oref after the code you posted.

It looks like somewhere after that code there is a:

Set CBORDRequest.encodedMessage=CBORDRequest

Beside that, my curiosity:

set a = $SYSTEM.Encryption.Base64Encode((pMsgOut.RawContent))
Why two parenthesis?

set CBORDRequest.encodedMessage = $Get(a)
Why using $Get for a variable that is indeed/for sure defined?

What product? IRIS, IRIS fir Health, HealthShare HC or HealthShare?

How did you created in the Management Portal the new database/namespace?

Do you need to decode a Base64 stream or you just need to read a stream to a string?

If so, then:

Set string=stream.Read($$$MaxStringLength)

Set string= $System.Encryption.Base64Decode(stream.Read($$$MaxStringLength))

If the B64 is "small" to fit a %String (~3.5MB or less), then just use $System.Encryption.Base64Decode()

To mesure the difference I've a differente approach then Robert and concentrate on same/different class calls without any additional overhead.
Please note that is my no means a demonstration of best/worst approach, IMHO there is a better solution, see my next post.

I've created two classes and simulated a big number of calls of a class method within the same class and same code calling a class method in a different class.

Class Community.perf.Class1
{

ClassMethod Compare(NumCalls As %Integer)
{
	Set SingleStart=$zh
	Do ..SingleClassCalls(NumCalls)
	Set SingleEnd=$zh
	Set MultiStart=$zh
	Do ..MultiClassCalls(NumCalls)
	Set MultiEnd=$zh
	Set Difference=(MultiEnd-MultiStart)-(SingleEnd-SingleStart)
	Set Percent=1-((SingleEnd-SingleStart)/(MultiEnd-MultiStart))*100
	Write "Same class calls: ",SingleEnd-SingleStart,!
	Write "Diff class calls: ",MultiEnd-MultiStart,!
	Write "Difference: ",Difference," ",Percent,"%",!
}

ClassMethod SingleClassCalls(NumCalls As %Integer)
{
	For i=1:1:NumCalls {
		Set x=..Compute(NumCalls)
	}
}

ClassMethod MultiClassCalls(NumCalls As %Integer)
{
	For i=1:1:NumCalls {
		Set x=##class(Community.perf.Class2).Compute(NumCalls)
	}
}

ClassMethod Compute(Num As %Integer)
{
	;Quit Num
	Set ret=Num
	Quit ret
}

}

Class Community.perf.Class2
{

ClassMethod Compute(Num As %Integer)
{
	;Quit Num
	Set ret=Num
	Quit ret
}

}

Calling the Compare() method with 100M iterations the result is:

EPTEST>do ##class(Community.perf.Class1).Compare(100000000)
Same class calls: 20.992929
Diff class calls: 31.460201
Difference: 10.467272 33.27147210534351%

Please note that changing the Compute() method in both classes to:

ClassMethod Compute(Num As %Integer)
{
    Quit Num
}

Makes a BIG difference:

EPTEST>do ##class(Community.perf.Class1).Compare(100000000)
Same class calls: 4.606181
Diff class calls: 5.52639
Difference: .920209 16.6511773508565266%

Using the first method code it adds the handling of the stack, therefore it takes longer and, for 100M calls, the difference is noticeable.
I think the first with "some" stack handling is a more realistic use case.

In conclusion, there is a difference and is measurable. Is it noticeable? Not much, IMHO in a computation that probably takes many minutes duplicating codes is not worth the gain.

There is however a better approach without duplicating the code, see my next post.

Ciao Robert,

I'm not sure your test address the original question, that is:

"whenever you call code outside of the routine as opposed to calling code in the same routine, some execution speed is lost"

In your test1 you do:

[call class method] -> [call class method in other class] -> [call a function in same class]

In your test2 you do:

[call class method] -> [call a function in same class]

This way you are not comparing "call code outside of the routine as opposed to calling code in the same routine", you are ADDING an additional call/level.

In addition, to measure the time penalty for calling inside/outside "routine" (or class), adding 100M global access does not help in getting a reliable measure because too many factors may change the time measured between different runs.
Finally a doubt, are we sure that calling a function and calling a class method is a fair comparison? May be or may be not, I don't know.

Would you mind to post the full/actual code you used?

...whenever you call code outside of the routine as opposed to calling code in the same routine, some execution speed is lost. For reports churning through millions of transactions this lost speed might be noticeable.

Can you reproduce this with a small/simple self contained example using code in same class/routine and same code calling different classes/routines where the difference is noticeable?