#Globals

4 Followers · 234 Posts

Globals are multidimensional sparse arrays which are stored in InterSystems Data Platform. Everything in InterSystems Products is stored in Globals: Classes, Tables, Documents, Code.

Documentation.

Article Vachan C Rannore · Aug 18, 2025 3m read

While starting with Intersystems IRIS or Cache, developers often encounter three core concepts: Dynamic Objects, Globals & Relational Table. Each has its role in building scalable and maintainable solutions. In this article, we'll walk through practical code examples, highlight best practices, and show how these concepts tie together. 

1. Working with Dynamic Objects:

Dynamic objects (%DynamicObject and %DynamicArray) allow developers to manipulate JSON-like structures directly in Objectscript. They are especially useful for modern applications that need to parse, transform or generate JSON.

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Article Davi Massaru Teixeira Muta · Feb 24 9m read

Global Guard AI

1 Introduction

In environments that use InterSystems IRIS, globals are the physical foundation of data storage. Although system queries and administrative tools exist for metric inspection, global growth analysis is usually reactive: the problem is generally only noticed when there is disk pressure or performance impact.

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Article Jonathan Card · Jan 25 5m read

There seems to be a generous use of ClassMethods in ObjectScript code generally. I hope my own experiences aren't representative, but I bet they are. Forgive me for giving away the ending of this article, but in short: don't use them. Unless you can make a pretty convincing case that you have to, just never use them.1

What is a ClassMethod? In an ObjectScript class, you can define methods in two different ways: in a Method, you must instantiate an instance of the class to call the method, and in a ClassMethod, you can call the method without instantiating the class. Of course, in a ClassMethod, you don't have access to any properties of the object (because there's no object), but you can access globals (they are global, after all) and Parameters (which are class constants).

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Article Jorge Jaramillo Herrera · Jan 9 9m read

1-command only required for an entire IRIS instance for Data Science projects, and leveraging this to compare query methods' speed (Dynamic SQL, Pandas Query, and Globals).

Before joining InterSystems, I worked in a team of web developers as a data scientist. Most of my day-to-day work involved training and embedding ML models in Python-based backend applications through microservices, mainly built with the Django framework and using Postgres SQL for sourcing the data.

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Article Neil Shah · May 12, 2025 7m read

Introduction

Hello! In this article, I will be discussing database degrade, a type of data integrity issue one can face when using IRIS. First, I will be going over a review of the structure of IRIS databases. I'll then discuss how database degrade can manifest and common causes of degrade issues. I'll then conclude with general tips we give our customers about how to prevent or prepare for database degrade issues.

IRIS Database Structure

What exactly is a database? An IRIS database is a single file that consists of a fundamental unit called the "block".

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Article Andreas Schneider · Apr 22, 2025 4m read

When using standard SQL or the object layer in InterSystems IRIS, metadata consistency is usually maintained through built-in validation and type enforcement. However, legacy systems that bypass these layers—directly accessing globals—can introduce subtle and serious inconsistencies.

Understanding how drivers behave in these edge cases is crucial for diagnosing legacy data issues and ensuring application reliability.
The DATATYPE_SAMPLE database is designed to help analyze error scenarios where column values do not conform to the data types or constraints defined in the metadata.

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Article Parani.K · Mar 2, 2025 8m read

Parallel query hinting boosts certain query performances on multi-processor systems via parallel processing. The SQL optimizer determines when this is beneficial. On single-processor systems, this hint has no effect.

Parallel processing can be managed by:

  1.  Setting the auto parallel option system-wide.
    
  2. Using the %PARALLEL keyword in the FROM clause of specific queries.
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Article Tomoko Furuzono · Nov 6, 2025 2m read

InterSystems FAQ rubric

When exporting using the Export() method of the %Library.Global class, if the export format (fourth argument: OutputFormat) is set to 7, "Block format/Caché block format (%GOF)," mapped globals cannot be exported (only globals in the default global database of the namespace are exported). To export mapped globals in "Block format/Caché block format (%GOF)," specify the database directory to which you want to map them in the first parameter of %Library.Global.Export().

An example of execution is shown below.

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Article Harshitha · Oct 22, 2025 2m read

Hello community,

I wanted to share my experience about working on Large Data projects. Over the years, I have had the opportunity to handle massive patient data, payor data and transactional logs while working in an hospital industry. I have had the chance to build huge reports which had to be written using advanced logics fetching data across multiple tables whose indexing was not helping me write efficient code.

Here is what I have learned about managing large data efficiently.

Choosing the right data access method.

As we all here in the community are aware of, IRIS provides multiple ways to access data. Choosing the right method, depends on the requirement.

  • Direct Global Access: Fastest for bulk read/write operations. For example, if i have to traverse through indexes and fetch patient data, I can loop through the globals to process millions of records. This will save a lot of time.
Set ToDate=+H
Set FromDate=+$H-1 For  Set FromDate=$O(^PatientD("Date",FromDate)) Quit:FromDate>ToDate  Do
. Set PatId="" For  Set PatId=$Order(^PatientD("Date",FromDate,PatID)) Quit:PatId=""  Do
. . Write $Get(^PatientD("Date",FromDate,PatID)),!
  • Using SQL: Useful for reporting or analytical requirements, though slower for huge data sets.
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Article Vachan C Rannore · Sep 15, 2025 2m read

Starting out with ObjectScript, it is really exciting, but it can also feel a little unusual if you're used to other languages. Many beginners trip over the same hurdles, so here are a few "gotchas" you'll want to watch out for. (Also few friendly tips to avoid them)


NAMING THINGS RANDOMLY

We have all been guilty of naming something Test1 or MyClass just to move on quickly. But once your project grows, these names become a nightmare. 

➡ Pick clear, consistent names from the start. Think of it as leaving breadcrumbs for your future self and your teammates.


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Article Beatrice Zorzoli · Sep 10, 2025 4m read

I joined InterSystems less than a year ago. Diving into ObjectScript and IRIS was exciting, but also full of small surprises that tripped me up at the beginning. In this article I collect the most common mistakes I, and many new colleagues, make, explain why they happen, and show concrete examples and practical fixes. My goal is to help other new developers save time and avoid the same bumps in the road.

1. Getting lost among system classes and where to start

The issue: ObjectScript/IRIS ships with many system classes and packages (%Library, %SYS, %Persistent, %SQL, etc.).

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Article Yuri Marx · Dec 16, 2024 2m read

The best way to list, edit, save and delete globals is using an IDE. Now, it is possible if you use VSCode. It is also possible to save globals using yaml files. Perform the following steps:

1. Get an InterSystems IRIS instance and install the application iris-global-yaml: 

zpm:USER>install iris-global-yaml

2. If you just to want an InterSystems IRIS trial for tests git clone and run on docker:

git clone https://github.com/yurimarx/iris-global-yaml.git
docker-compose up -d --build

3. Go to https://openexchange.intersystems.

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Article Yuri Marx · Dec 19, 2024 14m read

VSCode is the most used IDE in the world. It is strategic have more extensions for VSCode for InterSystems technologies to keep increasing the developer community.

My new app IRIS VSCode Global Editor is an excellent sample to learn how to create extensions to IRIS. You can check it on https://openexchange.intersystems.com/package/IRIS-Global-VSCode-Editor.

To be ready to create extensions for VSCode

From https://code.visualstudio.com/api/get-started/your-first-extension you have all steps to get ready, but I will detail here to you.

1.

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Article Megumi Kakechi · Aug 15, 2024 3m read

InterSystems FAQ rubric

Temporary globals stored in the IRISTEMP/CACHETEMP databases are used when a process does not need to store data indefinitely, but requires the powerful performance of globals. The IRISTEMP/CACHETEMP databases are not journaled, so using temporary globals does not create journal files.

The system uses the IRISTEMP/CACHETEMP databases for temporary storage and are available to users for the same.

For more information about temporary globals and the IRISTEMP database, see the following document:
Temporary Globals and the IRISTEMP Database

The globals used as temporary are:

1.

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Article Chad Severtson · Apr 12, 2023 8m read

Spoilers: Daily Integrity Checks are not only a best practice, but they also provide a snapshot of global sizes and density. 
Update 2024-04-16:
  As of IRIS 2024.1, Many of the below utilities now offer a mode to estimate the size with <2% error on average with orders of magnitude improvements in performance and IO requirements. I continue to urge regular Integrity Checks, however there are situations where more urgent answers are needed.

  • EstimatedSize^%GSIZE- Runs %GSIZE in estimation mode.   
  • ##class(%Library.GlobalEdit).GetGlobalSize(directory, globalname, .allocated, .used.
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Article Vadim Aniskin · Mar 13, 2024 4m read

JSON is a lightweight data interchange formatfor representing and exchanging data between a server and a web application. Its popularity has led to its widespread use in applications based on InterSystems technology, as well as demand for a converter that transforms globals to JSON and back. Therefore, @Evgeny Shvarov suggested developing Global->JSON->Global converter. Implementing such a converter is important to ensure interoperability, simplify data exchange, support web services, and provide a standardized approach to data representation across different software ecosystems. This article, the second in the "Implemented Ideas" series, focuses on several projects created by the legend of InterSystems Developer Community @Robert Cemper that deal with this task:

 

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Article Brendan Bannon · Dec 27, 2016 8m read

The Art of Mapping Globals to Classes (4 of 3)

The forth in the trilogy, anyone a Hitchhikers Guide to the Galaxy fan?

If you are looking to breathe new life into an old MUMPS application follow these steps to map your globals to classes and expose all that beautiful data to Objects and SQL.

If the above does not sound familiar to you please start at the beginning with the following:

The Art of Mapping Globals to Classes (1 of 3)

The Art of Mapping Globals to Classes (2 of 3)

The Art of Mapping Globals to Classes (3 of 3)

This one is for you Joel!

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Article Robert Cemper · Nov 19, 2023 2m read

There are situations when your only access to a server is using a web browser,
and there is just no chance of a Terminal or Console access.
The Online Demo Server is such a case.

So you have WebTerminal. That's fine for ObjectScript and Embedded Python.

But my demo is straight Java. And is interactive.
$ZF(-100...) is some aproach. But it's rater batch-oriented and not interactive.
@Enrico Parisi  presented a nice extension to WebTerminal recently.
It's close to my own packageWebCommand that I presented a year ago.

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Article Robert Cemper · Nov 15, 2023 2m read

This is the related article to the package in Java Contest. 
I decided to present a CRUD++ Global Editor based on IRIS Native API for Java.
++ because it’s a little bit more than just Create, Read, Update, Delete
Visualization of a global is always important to review results immediately.

  • For this purpose, I have extended the API with a Tree Viewer that mimics  ZWrite and allows also the examination of subtrees.
  • A $Query Style Navigator Forward and Reverse operating for easy finding the Global node of interest.
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Article Alex Woodhead · Sep 5, 2023 8m read

Overview

The online documentation contains a reference Defining and Using Class Queries -

Customizing Stored Procedures with ObjectScript directly has been useful to access NoSQL storage and external messaging via integration, to present output in tabular format.

For example: An application that already uses 90% SQL interaction from a front end, can then also extend this access to the other 10% of required platform functionality, via the same SQL access.

The purpose of this article is to explore how to achieve the same effect via Embedded Python methods.

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Article Robert Cemper · Aug 17, 2023 1m read

Inspired by a Question from @Evgeny Shvarov and a Reply from @Ashok Kumar T
I have created a base for Global download as XML file

How to use:
 
just call the page like http://<your_server>/csp/samples2/dc.Gdown.cls?GBL=global_name

gbl-name  without the initial ^ (caret)
The output has a default name <global_name>.XML  Your choice is available.

Known Limits:

  • you have to install it at your sourcing server
  • it is not tested/working across namespaces
  • there is no partial download
  • error handling is just basic or missing

There is space for personal improvements.
and this is it:

Class dc.Gdown Extends %CSP.
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Article Robert Cemper · Aug 10, 2023 3m read

As noted in the previous article Native API has some limits.
So I did some research on a more Terminal-like interface that
provides me with access like a console or the IRIS terminal
to allow my  $QUERY over a global and other nice commands
that are not supported/mapped in NativeAPI for ObjectScript.

The basic tools are well-prepared and available.

  • Connection() creates a fully operational and stable partition for me
  • Function() allows calling any routine or method I need
  • similar ClassMethodValue and ClassMethodVoid

There is just no method CommandLine and some already prepared code is needed.

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Article Mihoko Iijima · Jul 20, 2023 4m read

InterSystems FAQ rubric

You can search for a specific global variable in the journal file using the ByTimeReverseOrder query of the %SYS.Journal.File class and the List query of the %SYS.Journal.Record class.

The role of each query is as follows.

A) %SYS.Journal.File query of the ByTimeReverseOrder class

You can get the journal file name. Results are returned in descending order of journal file name. 

USER>set stmt=##class(%SQL.Statement).%New()

USER>set status=stmt.%PrepareClassQuery("%SYS.Journal.File","ByTimeReverseOrder")

USER>set rs=stmt.%Execute()

USER>while rs.%Next() { write rs.
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Article Eduard Lebedyuk · Aug 3, 2020 3m read

InterSystems IRIS currently limits classes to 999 properties.

But what to do if you need to store more data per object?

This article would answer this question (with the additional cameo of Community Python Gateway and how you can transfer wide datasets into Python).

The answer is very simple actually - InterSystems IRIS currently limits classes to 999 properties, but not to 999 primitives. The property in InterSystems IRIS can be an object with 999 properties and so on - the limit can be easily disregarded.

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Article Mihoko Iijima · Jul 13, 2023 2m read

InterSystems FAQ rubric

It can be obtained by using the Size query of the system-provided %SYS.GlobalQuery class.

See the sample code below for usage examples.
*Please check the class reference for specifying columns and parameters.

 set dir="C:\intersystems\iris\mgr\user" // IRIS.DAT(or CACHE.DAT) folder
 set rs = ##class(%ResultSet).%New("%SYS.GlobalQuery:Size")
 do rs.Execute(dir) // You can also specify a mask with the 3d parameter
 while (rs.Next()) { 
   set gname= rs.Get("Name") // global name
   set gsize= rs.Get("Used MB") // global size (MB)
   write gname," : ",gsize,!
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Article Robert Cemper · Jun 20, 2022 7m read

My major interest is  Working with Globals in Embedded Python.
So I checked the available official documentation.

#1 Introduction to Globals
an attempt of a generic description of what a global is. Pointing to

#2 A Closer Look at ObjectScript
But where is Embedded Python ?
Way down you see

#3 Embedded Python

3.1 Embedded Python Overview
3.1.1 Work with Globals

Great if you have never seen a Global before
Otherwise a shocking primitive example
3.2 Using Embedded Python
Last hope: >>> but there is just NOTHING visible.
This is more than just disappointing! Even IRIS Native API for Python is more detailed.

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Article Brendan Bannon · Aug 29, 2016 7m read

The Art of Mapping Globals to Classes 1 of 3

Looking to breathe new life into an old MUMPS application?  Follow these steps to map your existing globals to classes and expose all that beautiful data to Objects and SQL.

By following the simple steps in this article and the next two you will be able to map all but the craziest globals to Caché classes.  For the crazy ones I will put up a zip file of different mappings I have collected over the years.  This is NOT for new data; if you don’t already have existing global please just use the default storage.

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Article Robert Cemper · Jan 30, 2023 2m read

The similarity between JSON objects + arrays and Globals in IRIS or Caché is evident.
With small and medium size JSON objects navigation across %Dynamic Objects is comfortable.
But with large and/or deep cascaded objects it becomes a challenge.

The presented tool offers 3 variants

  • loading an already existing %Dyamic object or Array into a global of your choice
  • loading a %Stream containing a JSON object into a global of your choice
  • loading an external File containing a JSON object into a global of your choice
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