Example Schema1
<?xml version="1.0" encoding="UTF-8"?>
<s:schema xmlns:s="http://www.w3.org/2001/XMLSchema" elementFormDefault="qualified" attributeFormDefault="unqualified">
<s:complexType name="Schema1">
    <s:sequence>
        <s:element name="Max_Results">
            <s:simpleType>
                <s:restriction base="s:long">
                    <s:minInclusive value="1"/>
                </s:restriction>
            </s:simpleType>
        </s:element>
        <s:element name="Home-State">
            <s:simpleType>
                <s:restriction base="s:string">
                    <s:maxLength value="2"/>
                    <s:minLength value="2"/>
                </s:restriction>
            </s:simpleType>
        </s:element>
        <s:element minOccurs="0" name="Office-State" type="s:string"/>
        <s:element minOccurs="0" name="Name-Startswith" type="s:string"/>
    </s:sequence>
</s:complexType>
</s:schema>

Example Schema2

<?xml version="1.0" encoding="UTF-8"?>
<s:schema xmlns:s="http://www.w3.org/2001/XMLSchema" elementFormDefault="qualified" attributeFormDefault="unqualified">
    <s:complexType name="Schema2">
    <s:sequence>
        <s:element minOccurs="0" name="Results" type="ArrayOfSchema2Result"/>
    </s:sequence>
</s:complexType>
<s:complexType name="ArrayOfSchema2Result">
    <s:sequence>
        <s:element maxOccurs="unbounded" minOccurs="0" name="Schema2Result" nillable="true" type="Schema2Result"/>
    </s:sequence>
</s:complexType>
<s:complexType name="Schema2Result">
    <s:sequence>
        <s:element minOccurs="0" name="Home-Address" type="Address"/>
        <s:element minOccurs="0" name="Office-Address" type="Address"/>
        <s:element minOccurs="0" name="Person-Name" type="s:string"/>
        <s:element minOccurs="0" name="Person-ID" type="s:long"/>
    </s:sequence>
</s:complexType>
<s:complexType name="Address">
    <s:sequence>
        <s:element minOccurs="0" name="Street">
            <s:simpleType>
                <s:restriction base="s:string">
                    <s:maxLength value="80"/>
                </s:restriction>
            </s:simpleType>
        </s:element>
        <s:element minOccurs="0" name="City">
            <s:simpleType>
                <s:restriction base="s:string">
                    <s:maxLength value="80"/>
                </s:restriction>
            </s:simpleType>
        </s:element>
        <s:element minOccurs="0" name="State">
            <s:simpleType>
                <s:restriction base="s:string">
                    <s:maxLength value="2"/>
                </s:restriction>
            </s:simpleType>
        </s:element>
        <s:element minOccurs="0" name="Zip">
            <s:simpleType>
                <s:restriction base="s:string">
                    <s:maxLength value="5"/>
                </s:restriction>
            </s:simpleType>
        </s:element>
    </s:sequence>
</s:complexType>
</s:schema>
 

Nope

https://learning.intersystems.com/pluginfile.php/15097/mod_resource/con…

Next: 
Download PDF  
downloads a html page but with .PDF termination.

so $lb($$$FIXSTR,text)  since $L(text) is included there anyhow
and $$$FIXSTR tells you that it's < 32
 

why not $lb(166,"Fringe")  ?

Thank you, Dan!
I was pretty sure to miss some cases.
SOID is probably the one nobody else would be aware of that it exists.   

similar in practice if you  run bookkeeping as a service.
master has full access and has the responsibility  for the content. Using Work class
clients have just read access to most fields. Using Client class.
I didn't say tax control doesn't see everything.  Using Government class

I see. It's hard generated
IndexNext distracted me

But you may call it individually. With your sequence then.

ok.
You followed the direction: that you mark the "unavailable" value by a UNIQUE value.
So for SQL it's NOT NULL.
I agree with you that NullString (COS) => String of length 0 and NULL(SQL) is confusing 
[since invention of SQL in the late 60ties]

Take a closer look to %Library.Date, %Library.TimeStamp, %Library.Integer
and you will see the various methods for LogicalTo.....
The switch you select applies to the final presentation only. Not to internal calculations.

OK, that looks better 

now go to Mgmt Portal /SQL and verify for both tables that you see values in column Selectivity (marked)

IF THERE IS NO SELECTIVITY ANY QUERY PLAN IS JUST GUESSWORK.

if this is empty Query Generator just can guess and do a lot of unnecessary extra work.

so got Tune Table click it

and this you get there information that the Query Generator allows to make useful optimizations (marked)

Next enter your specific  query and click to "Show Plan"
that marked information tells you what is happening and Relative Cost qualifies the expected performance. 

This query plan tells you what is really happening.

much faster and straight forward string conversion then $ZD* stuff doing unnecessary conversions .

I assume you know where you get your email address from.
The rest is straight COS and your code my look like this

Exact !
That's the way it was done since ....  {ever}

You have to set $ZTRAP again at the begin:
Or start with do infile^myroutine ....
at the 1. run it is set i line 3
you my also pass the filename as parameter 

Taskmanager is a part of Caché System Management and you should read the Docs.
JOB is a COS command also used in Taskmanager but not only. Any routine may use it.

So your Request / Question is just not clear