Although InterSystems allowed unlicensed use (with some limitations) of Caché by educational institutions very few colleges/universities took advantage of this.  The exception seemed to be universities in Russia.  When we had contests for the best Caché applications we would offer the university winner a free trip to Global Summit.  However, a recent Russian student was unable to attend because she could not get a Visa to visit the US.

Maybe IRIS with embedded Python could help increase university interest in IRIS databases.

The %Library.DynamicArray and %Library.DynamicObject class objects are stored only in process memory and are not affected by the 3641144 character string length of ObjectScript strings.  But they are affected by the amount of virtual memory that the operating system will grant to a process so avoid having many such large things active.  These Dynamic Objects generally hold JSON format data but they can also hold ObjectScript values.  The %ToJSON(output) method can change the contents of Dynamic Object into JSON text and it will send that text to 'output', which can be a file, a device or a %Stream.  If you need to persist a Dynamic Object in a database then you can use %ToJSON(globalstream) to persist the JSON text in a %Stream.GlobalCharacter or %Stream.GlobalBinary class object.  There is a %FromJSON(input) which can build a new Dynamic Object from 'input' which is JSON text from a string, a file, a device or a %Stream.  In recent versions of IRIS, the %Get(key,default,type) and %Set(key,value,type) methods can let you choose 'type' as some form of %Stream so you can examine and modify elements of a Dynamic Object when that element needs to be larger than 3614411 characters.  The default %Stream-s generated by the %Get method use the %Stream.DynamicBinary and %String.DynamicCharacter classes, which also store data in process memory so you should avoid having many such large streams active at the same time.  They can be copied out to other streams which can be stored a database or into a file or a device.

The original ANSI M (also known as ANSI MUMPS) standard did not distinguish between a canonical numeric string versus a number.  Many early implementations of this standard used strings of numeric characters as the internal representation of a number and did arithmetic on character strings instead of converting the numeric string to a binary representation and then using the hardware binary arithmetic instructions.  The result of a numeric operation would always be a character string using the canonical numeric representation.

In such an implementation there was no way to tell the difference between the character string "123" and the literal 123 since "123" was the canonical numeric string representation for that value.  For performance reasons, InterSystems ObjectScript has several different internal representations it can use for the number 123.  It can use the three character strintg "123"; it can use the 32-bit binary integer 123; it can use one of several representations of 123 in ObjectScripts' decimal floating point representation which has a 64-bit binary integer significand combined with an 8-bit power-of-10 exponent.  Writing 12300E-2 will usually be represented with the decimal floating-point representation and not with the integer repersentation.

The command WRITE $LISTSAME($LISTBUILD("123"),$LISTBUILD(12300E-2)) will write 1 because the string "123" and the numeric literal 12300E-2 are the same value.  However WRITE $LISTBUILD("123")=$LISTBUILD(12300E-2)) will write 0 because the $LISTBUILD will will generate different string encodings in this situation even though the values are considered to be identical.  Although $LISTBUILD could convert different internal representations into identical $LIST strings, it is faster just to place the internal representation into the generated binary string.  This is why you must use $LISTSAME when you want to check if two $LIST strings contain the same value.

There are a very few functions built into ObjectScript that have a behavior that depends on the internal representation of the argument.  All of these function were inherited when InterSystems extended ObjectScript to have a compatible feature with the language implemented by other vendors who produced extended M/MUMPS systems.  The most common function is $ZHEX(x) which turns a hex string to a decimal number and which turns a decimal number into a string.  Thus, WRITE $ZHEX("10") will write number 16 while WRITE $ZHEX(10) will write the string "A".  If you want to convert variable 'x' from an integer to hex then you need to write $ZHEX(+x) to make sure 'x' is using an internal numeric representation.  If you want to convert variable 'x' from hex to an integer then you need to write $ZHEX(x_"") to make sure 'x' is using the string internal representation.

One additional note:  The literal 123.0 will use an internal numeric representation so WRITE "123.0"=123.0 will WRITE 0 since a string equality comparison operator will be done between the literal string "123.0" and the canonical numeric string "123".  However, WRITE +"123.0"=123.0 will WRITE 1 because the unary plus operator converts the first operand to a numeric representation and then the string equality operator converts both numeric operands into their canonical numeric string representations making the string equality operation be the same as "123"="123".

The class reference at docs.intersystems.com will tell you about InterSystems supplied classes but it will not tell you about user written classes that are extended from a system supplied abstract classes nor about a user class extended from other user classes.

Look at the following with your browser:  http://localhost:57772/csp/documatic/%25CSP.Documatic.cls , where localhost is the system name on which you are running Caché and 57772 is the WebServer port of your Caché instance.  (If you were running IRIS your WebServer port would look something like 52773.)

Once you are on the Class Reference web page then navigate to find the particular class in which you are interested.  Look at the SubClasses Summary section to find inherited classes.  You can click on the an inherited class name to navigate to the Class Reference information of that class.

Leon has not made a return comment and his original question would be ambiguous to some people.  I often call the " character, the 'double quote' character while I often call the ' character the 'single quote' character.  Other names I might use for the " character are 'quotation character' or 'ditto mark'.  Other names for the ' character would be 'apostrophe' or 'apostrophe quotation character'.  [[Notice I am using apostrophe quotation characters in this comment.]]  I might describe "" characters as 'doubled quotation characters' or 'doubled double quotes'.

Since Leon asked to 'remove double quotes (") from a string' my first impression would be to remove all " characters from the string.  I.e., every $C(32) should be removed.  If Leon wanted to only remove 'doubled quotation characters' then he probably would have written 'remove double quotes ("") from a string'.

If your long strings are coming from JSON representation then

   Set DynObj=##class(%DynamicObject).%FromJSON(...)

will create a  %Library.DynamicObject or %Library.DynamicArray object in memory containing the JSON array/object elements where the sizes are limited only by the amount of virtual memory the platform will allocate to your process.  A string element of an object/array can have many gigabytes of characters (virtual memory permitting) and you can get the value of such a huge string element in the form of an in-memory, read-only %Stream doing:

   Set StreamVal=DynObj.%Get(key,,"stream")

in cases where DynObj.%Get(key) would get a <MAXSTRING>.

The StreamVal (class %Stream.DynamicBinary or %Stream.DynamicCharacter) is a read-only, random-access %Stream and it shares the same buffer space as the 'key' element of the DynObj (class %Library.DynamicObject) so the in-memory %Stream does not need additional virtual memory.

You can then create a persistent object from a class in the %Steam package (%Stream.GlobalBinary, %Stream.GlobalCharacter, %Stream.FileBinary, %Stream.FileCharacter, or some other appropriate class.)  You can then use the CopyFrom method to populate the persistent %Stream from the  read-only, in-memory %Stream.DynamicBinary/Character.

Consider the following:

USER>set num1=1,str1="""1""",num2=2,str2="""2""",num10=10,str10="""10""",abc="abc"

USER>set (x(num1),x(str1),x(num2),x(str2),x(num10),x(str10),x(abc))=""            

USER>set i="" do { set i=$order(x(i))  q:i=""   write i,! } while 1               
1
2
10
"1"
"10"
"2"
abc

The WRITE command treats its expression arguments as ObjectScript string expressions so any argument expression with a numeric value is converted to a string value containing characters.  Note that variables str1 and str2 are strings containing 3 characters starting with one double-quote character, ".  The str1 and str2 values sort among other strings where the first character is a double-quote character.  When you print these subscript strings, the subscripts from variables num1 and num2 print as one character strings,  the subscript from variable num10 prints as a two character string, the subscripts from variables sub1, sub2 and abc print as three character strings and the subscript from variable str10 prints as a 4 character string.

If you use ZWRITE instead of WRITE then ZWRITE will add extra quote marks, will add $C(int) expression syntax and will add other things so that the textual representation that is printed does not contain any unprintable characters and you can see trailing white space.

You might consider looking at the ##class(%GlobalEdit).Create(...) method.  It has a 'Collation' argument which allows you to change the collation from the namespace default.  Just choose a collation that does *NOT* sort canonical numeric strings in front of non-numeric strings.

I don't recommend ever changing the default collation of a namespace as many utility routines depend on canonical numeric strings sorting in numeric order and not sorting in string order.  Those utilities may not work in such a namespace.

When asking about a 'ROUTINE' you may be asking about the difference between a 'Routine', 'Procedure', 'Subroutine', 'Function', 'Label', 'Class' and 'Method'

A 'Routine' is a source code file with name like 'myroutine.mac'.  Source code can also be a 'Method' which is found in a 'Class' file with a name like 'myclass.cls"

A Routine file can contain Procedures, Subroutines, Functions and Labels.  See https://docs.intersystems.com/irislatest/csp/docbook/DocBook.UI.Page.cls?KEY=GCOS_usercode#GCOS_usercode_overview for some InterSystems documentation.

You can call a subroutine with the statement 'DO MySubroutine^myroutine(arg)'; You can call a function with the expression '$$MyFunction^myroutine(arg)';  You can call the procedure 'MyProcedure^myroutine(arg)' using either the syntax for a subroutine call or function call depending on whether you need the value returned by the procedure; and, You can Goto the source code following a label with the statement 'GO MyLabel^myroutine'.  If you reference a subroutine/function/procedure/label inside a Routine file (e.g. myroutine.mac) and that subroutine/function/procedure/label access (e.g.$$MyFunction^myroutine(arg)) is referencing a name defined in the same Routine file then you do not have to specify the ^Routine name in the call syntax (e.g. $$MyFunction(arg)).

The local variables used inside a subroutine or function are 'public' variables and those named variables are shared with all other subroutines and functions.  You can use the NEW command inside a subroutine or function to temporarily create new public variables without modifying previous instances of public variables with the same names.

The local variables used inside a procedure are private variables.  The private variables are only available inside the procedure.  Those names do not conflict with variables used by any caller of the procedure.  Those names are not available in any code called by the procedure although it is possible to pass either the private variable or the value of the private variable as an argument when calling out of a procedure.  The declaration of a procedure can optionally include a list of public variables.  Names in public list reference the public variable when they are accessed by code in the procedure.  You can use the NEW command with an argument that is a public variable within a procedure.  A label defined inside a procedure is also private and it cannot be referenced by any GO command outside that procedure.

Methods defined in a class file default to being a procedure with private variables and private labels.  However, it is possible to specify that a method is a subroutine or function.   Also, a method procedure declaration can optionally include a list of global variables.

The %GlobalBinaryStream class is deprecated and newly written code should instead use %Stream.GlobalBinary.  Of course, existing code that is not needing modification can continue using %Library.GlobalBinaryStream.
.  

The %DynamicAbstractObject classes first appeared in version 2016.2 so JSON support in software versions 2017.x will not have many of the more recent new features.  If possible, you really should upgrade to more recent InterSystems versions so you can use more modern functionality.

You should not follow the recommendation to modify the $ZTIMEZONE system variable.  See this warning in the $ZTIMEZONE documentation:

Note:
Changing the $ZTIMEZONE special variable is a feature designed for some special situations. Changing $ZTIMEZONE is not a consistent way to change the time zone that Caché uses for local date/time operations. The $ZTIMEZONE special variable should not be changed except by those programs that are prepared to handle all the inconsistencies that result.

On some platforms there may be a better way to change time zones than changing the $ZTIMEZONE special variable. If the platform has a process-specific time zone setting (for example, the TZ environment variable on POSIX systems) then making an external system call to change the process-specific time zone may work better than changing $ZTIMEZONE. Changing the process-specific time zone at the operating system level will change both the local time offset from UTC and apply the corresponding algorithm that determines when local time variants are applied. This is especially important if the default system time zone is in the Northern Hemisphere, while the desired process time zone is in the Southern Hemisphere. Changing $ZTIMEZONE changes the local time to a new time zone offset from UTC, but the algorithm that determines when local time variants are applied remains unchanged

If you change $ZTIMEZONE then the local time will change but local changes in timezone rules (e.g., entering/leaving Daylight Saving Time, DST) will not be changed.  If the system is in the Northern Hemisphere but you want a local time in the Southern Hemisphere (or vice-versa) then DST changes will be backwards.  Also, DST rules near the equator can be very different from the DST rules at latitudes closer to the poles.  If the system local timezone and the modified local timezone are in different countries then the national date/time rules may be incorrect for the modified local timezone.

Using the $SYSTEM.Process.TimeZone(...) method suggested by Jon Willeke is the best way to modify the local timezone used by a Caché/IRIS process.  However, the 'TZ' environment variable modified by the $SYSTEM.Process.TimeZone(...) method requires an argument string that is specific to the Operating System under which Caché/IRIS is running.  Generally the Windows Operating System wants the TZ variable to contain a POSIX format timezone string while Unix/Linux systems want the TZ variable to contain an Olson format timezone string (sometimes called the IANA or ICU format timezone string.)  If you need dates/times using rules from the past then generally the Olson format will work much better than the POSIX format.

Aside from several arithmetic differences, the biggest difference between $INCREMENT AND $SEQUENCE occurs when "SET index=$INCREMENT(^global)" versus "SET index=$SEQUENCE(^global)" are being executed by multiple processes.

All the processes evaluating $INCREMENT(^global) on the same ^global variable will see a sequence of increasing integers.  No two processes will see the same integer returned.  The integers are given out in strict increasing time order and no integer value is skipped.

All the processes evaluating $SEQUENCE(^global) on the same ^global variable will see a sequence of increasing integers.  No two processes will see the same integer returned.  Because blocks of integers are assigned to processes, it is possible for one process to receive a larger integer in the sequence before some other process receives a smaller integer in the sequence.  If some process decides to stop processing integer values at some point then the larger integer values assigned to that process will be skipped and not returned as part of the sequence.

The $SEQUENCE function can have less multi-process overhead because integers in the sequence are assigned in blocks but $SEQUENCE does not guarantee a sequence of numbered tasks is assigned to processes in strictly increasing order.  Every process must continue processing numbered tasks until that particular process has been assigned a sequence number larger than the highest assigned task.  Just because one process has finished the highest assigned task does not mean that other processes are done with the earlier tasks (or have even started earlier tasks) and the sequence is only complete when every process has received a sequence number larger that the number of the final task.