Create a BS that sends messages to BO every X seconds - it makes production more complex and also queues might not guarantee that the method is executed on schedule.

You could try submitting the message to the head of the queue to be sure it gets processed right away.

I'll be interested to see others' thoughts on this as well, but one approach is:

• Create a new empty database for the globals
• Use GBLOCKCOPY or MERGE to copy each of the globals from the current DB to the new globals DB. I believe GBLOCKCOPY is faster than MERGE.
• After they are copied/merged to the new DB kill the globals in the currrent DB. This then becomes your routines DB.

Or you can do the opposite and export all of your routines from the current DB, import them into a new routines DB, then delete them from the current DB which becomes your globals DB. This would be faster than the first approach unless your globals are really small.

%System.OBJ.Load() imports and compiles classes and can be run from another routine or class.

You've written a pretty good description of the Production Generator included in IRIS for Health:
https://docs.intersystems.com/irisforhealthlatest/csp/docbook/DocBook.UI...

This presentation may be of interest:
https://learning.intersystems.com/course/view.php?id=1192

Have a look at $SCONVERT:
https://cedocs.intersystems.com/ens201513/csp/docbook/DocBook.UI.Page.cl...

USER>set tIEEE=$c(0,0,220,67) // bytes representing 0000000 00000000 11011100 01000011
 
USER>write $SCONVERT(tIEEE,"F4")
440

Here's a working example using <img> in a <table>. I don't think you can put an <img> inside an <item> or inside another <img>.

<table orient="col">
            <block width="40%">
                    <img src="http://localhost/logo.jpg" contentHeight="0.56in" contentWidth="2.33in" style="text-align:left"/>
            </block>
            <block width="40%">
                <table orient="col">
                        <item field='#(..pagetitle)#'/>
                </table>
            </block>
            <block width="20%" style="text-align:right;">
                  <item field='#(..subtitle)#'/>
             </block>
</table>

Here is the section in the docs that explains why this is happening and why @Eduard Lebedyuk asked if that class is persistent.
 

Business Process Execution Context

The life cycle of a business process requires it to have certain state information saved to disk and restored from disk, whenever the business process suspends or resumes execution. This feature is especially important for long-running business processes, which may take days or weeks to complete.

A BPL business process supports the business process life cycle with a group of variables known as the execution context. InterSystems IRIS automatically save the variables in the execution context and restores them each time the BPL business process suspends and resumes execution.

It seems like this approach would still work with a poolsize > 1. Of course each worker job will decide on its own if it should throttle or not.

There's no option for %DisplayFormatted to split the results into multiple parts automatically. You would need to write a custom method to do your CSV output with the logic you need. I can post some sample code that outputs CSV if that would be helpful.

8 hours for 16 million records at ~140 bytes/record seems really slow. I just did a test on a slow Windows VM and for a simple "SELECT *" for 16 million records @ 150 bytes/record, %DisplayFormatted took about 18 minutes to output the 2.4 GB CSV.

I suggest you contact the WRC to help look at where the bottleneck is.

In your assign action, there is a leading space in the property name:

<assign value='source.AttendingClinicians.GetAt(st).Code' property=' npicode' action='set' />

Have a look at the <pagebreak> element.

%XML.Reader and %XML.Document won't automatically update the original stream. You need to use %XML.Writer to output the %XML.Document into a stream.

set writer=##class(%XML.Writer).%New()
set outStream=##class(%Stream.GlobalCharacter).%New()
set tSC=writer.OutputToStream(.outStream)
set tSC=writer.Document(document)
write "Stream:[",outStream.Read(3000000),"]",!