Most IRIS developers use $LISTBUILD every day — often without even noticing it.

It is not just a convenient function for building lists. It is also the default internal format used to store row data, global values, and many intermediate structures inside the database engine.

Despite this, the actual binary representation of $LISTBUILD values is rarely discussed. Most developers rely on its behavior, but never look at how the data is really stored.

This article focuses strictly on the binary layout of $LISTBUILD values, based on direct inspection via zzdump.

During my work with customers and also following I often met the 
explicit or embedded question: What is this "GLOBALS" ?
I'll try to explain the history to unfold the context.

I need a %SYS.Python object that will be accessible from different processes. The goal is to avoid reinitializing the Python object whenever it is called. Ways that I checked and decided that it is NOT what I want:

• %-variables (process variables). Reusing only in the same process
• Save-and-restore via globals. Restoring means heavy initialization, which I want to avoid

Next, my ideas (none of them look like a silver bullet):

• Using Interoperability Production.

Hi Team,

We are currently running InterSystems Caché 2018 on an IBM AIX server and would like to configure the Cache instance to start automatically when the server boots or is rebooted.

Could you please provide the recommended steps or any official scripts/guidelines to enable auto-start for the Cache instance (QA2018) on AIX?

Additionally, if there are any best practices or prerequisites (such as filesystem mount options, service dependencies, or startup order) that we should consider, please share those as well.

Thanks,
Ganesh

Has anyone done this successfully?  Customer wants to receive HL7 data over https using OAUTH 2.0 client credentials.  I am assuming a custom Operation will be needed?  I tried using CoPilot for assistance but was unsuccessful.  I am not great with Object script :( 

#North American Demo Showcase entry. Answer the question below to be entered in the raffle!

⏯️ AI Assistants for the Unified Care Record Powered by Gemini

In this demo, you will see how Gemini works directly with FHIR data, and how it leverages the harmonized dataset provided by InterSystems Unified Care Record. It also showcases multiple AI assistants helping multiple groups of users, e.g. clinicians, patients.

🗣 Presenter: @Simon Sha, Sales Architect at InterSystems

#North American Demo Showcase entry. Answer the question below to be entered in the raffle!

⏯️ HL7 Validation Error Profiler: Rapid Insights into Batch HL7 Data Quality Issues

This demo highlights how HL7 validation logs can be transformed into scalable, actionable data quality insights using a lightweight application built on top of Health Connect.

• Batch ingestion and parsing of HL7 validation error logs into structured data
• Aggregation of errors by segment, field, and type to reveal systemic issues
• Interactive dashboard (Streamlit) for filtering, exploration, and root cause analysis
• Rapid identification of top error patterns across entire data feeds
• Natural language chatbot for intent-driven data investigation and querying
• PDF report generation for sharing clear, evidence-based feedback during data source onboarding 

Special thanks to @Henry Wojnicki for his contributions to designing and refining the application workflow.

🗣 Presenter: @Lynn Wu, Sales Engineer at InterSystems

Hi, Community!

Here's another way AI can speed up your processes—take a look! 👇

Generating Transformation Descriptions with the DTL Explainer

READY is right around the corner, and this year the Application Services team from InterSystems will be hosting a IPM Users GroupMeeting during the conference!This will be held Wednesday, April 29^th during lunch from 12:30 – 1:30 (lunch will be served at the meeting room).

Every great community is enriched by those who work tirelessly behind the scenes, crafting the knowledge and resources that help others grow. In the InterSystems Developer Community, one such person is @Derek Robinson — a dedicated educator, whose passion for teaching has helped shape how developers everywhere learn to work with InterSystems technologies.

👏 Let's take a closer look at Derek's journey in the InterSystems ecosystem.

Hi Community!

Thank you to everyone who participated in the "Suggest topics for our next free hands-on tutorials" sweepstakes! Your ideas and suggestions are invaluable and will definitely influence our tutorials roadmap! 

Now, it's time to announce the winner – watch the video to see the sweepstake drawing:

Introduction
InterSystems IRIS Adaptive Analytics is an optional extension that provides a business-oriented, virtual data model layer between InterSystems IRIS and popular Business Intelligence (BI) and Artificial Intelligence (AI) client tools. Adaptive Analytics is powered by AtScale, the AtScale documentation can be found at this link: https://documentation.intersystems.atscale.com

This article will showcase some AtScale features that can facilitate data analysis:

1. Cube creation
2. Excel visualization
3. Parallel Period
4. Queries
5. Snowflake
6. Security

7. Aggregates

READY is right around the corner, and this year the Application Services team from InterSystems will be hosting a Embedded Git Users GroupMeeting during the conference!This will be held Thursday, April 30^th during breakfast from 7:30 – 8:30 (breakfast will be served at the meeting room starting at 7:00am).

READY is right around the corner, and this year the Application Services team from InterSystems will be hosting a CCR Users GroupMeeting during the conference!This will be held Wednesday, April 29^th during breakfast from 7:30 – 8:30 (breakfast will be served at the meeting room starting at 7:00am).

The 2025.1.4 and 2024.1.6 maintenance releases of InterSystems IRIS^® data platform, InterSystems IRIS^® for Health^TM, and HealthShare^® Health Connect are now Generally Available (GA). These releases include the fixes for a number of recently issued alerts and advisories, including the following: 

• April 15, 2026 – Alert: Removal of InterSystems IRIS for Health and Health Connect 2024.1.4 and 2024.1.

I'm starting to play more with AI enabled coding. 
I've been using Github Copilot inside Visual studio code, which is very good at coming up with autocomplete suggestions that are accurate and useful. (Along with some utter rubbish, naturally).
For web development I'm starting to use Claude Code in VS Code to help create web sites and integrations. I want to see how it can help with IRIS development. 

However I can't get claude to read any iris code directly as I'm connected to my server via isfs server connections.

Summary

Issue

• The impacted versions of InterSystems IRIS for Health and Health Connect are being removed from WRC distribution sites due to issues identified in several FHIR and healthcare interoperability features.

We didn't start with a big AI strategy.

We had a legacy InterSystems Caché 2018 application, a lot of old business logic, and a practical need: build a new UI and improve code that had been running for years. At first, I thought an AI coding agent would help only with a small part of the work. Maybe some boilerplate, some REST work around the system, and a bit of help reading old ObjectScript.

In practice, it became much more than that.

Before finding the best solution for Supply Chain, we need to understand what Supply Chain is. Well, regardless of the language used, the term is known by the name already mentioned. For your information, the translation in Brazilian Portuguese is "Cadeia de Suprimentos" (Supply Chain), sometimes also called "Cadeia Logística" (Logistics Chain), but we will not dwell on the nomenclature, but rather on the meaning.

Hi, every one. Again, it's me!!😀😀

Recently I was trying to organize some learning materials for InterSystems IRIS😆, and realized that the resources are actually quite scattered.🤐

So I put together a list here—grouped by categories—for anyone who:

• is new to InterSystems
• or wants to go deeper into specific areas

Also adding some of my own experience on what worked (and what didn’t, may be only not work for me🤫🤐).

1. For starters

If you don’t know where to begin, start here:

• https://developer.intersystems.com/
• https://developer.intersystems.com/resources/
• https://developer.

Over the past year there have been a few DC articles offering MCP servers designed to connect to IRIS and help the AI features of VS Code and its cousins do a better job. For example:

• Hey chat, what's up with my Interoperability by @Dmitry Maslennikov 
• No-Hallucinate MCP: Real-time Routine Context for ObjectScript by @Jinyao 
• iris-mcp-atelier introduced by @Ernest Salas in his comment on the Claude Code vs ISFS. Has anyone cracked how to get one to see the other? post by @MarkCharlton.

I use cspa24.so Apache module to connect to IRIS. I have notified that idle Apache processes will always result in connections being kept open to the IRIS server, and thus some amount of IRIS processes being kept alive (and dedicated to those apache processes) because of those connections.

Eg: if I have 50 idle Apache processes, I will have 50 IRIS processes being kept alive in IRIS even if there is no client connection being made at that time. 

It's even worse with multiple Apache nodes and a load balancer.

Summary

Issue

• Deployments do not serve FHIR Server, bulk FHIR, FHIR SQL, or associated security user interfaces when using a non-default path prefix. For example, when using logical path configurations with Windows IIS, Apache, or other web servers.

This past weekend we ran into something odd. When we failed over our mirror from 2022.1.3 to 2025.1.3 the one of the Business Rules that was on what became the Primary (2025.1.3), had a rule within it that was removed back in January. When the Failover occurred, we had to scramble to backup, disable, and remove the Rule that shouldn't have been there. 

Both the Data and Code live within the same IRIS.dat that is the main MIRROR database for that Namespace. 

If this happened to one Class file, could it happen to others we do not know about?

Hi Community,

In our two preceding articles, we explored the fundamentals of the Interoperability Embedded Python (IoP) framework, including message handling, production setup, and Python-based business components.

In this third piece, we will examine advanced methodologies and practical patterns within the IoP framework that are pivotal for real-world interoperability implementations.
We will explore the following topics: 

✅ DTL (Data Transformation Language) in IoP
✅ JSON Schema Support
✅ Effective Debugging Techniques

Collectively, these features help us create maintainable, validated, and easily troubleshootable production-grade interoperability solutions.

The PACELC theorem was created by Daniel Abadi (University of Maryland, College Park) in 2010 as an extension of the CAP theorem (created by Eric Brewer - Consistency, Availability, and Partition Tolerance). Both help design how to architect the most suitable operation of data platforms in distributed environments under the aspects of consistency versus availability. The difference is that PACELC also allows analysis of the best option for non-distributed environments, making it the gold standard for considering all possible scenarios to define your deployment topology and architecture.

The CAP theorem states that in distributed systems, it is not possible to have consistency, availability, and partition tolerance simultaneously, requiring a choice of two out of three, according to the following diagram.

Source: https://medium.com/nerd-for-tech/understand-cap-theorem-751f0672890e

hi 😊,

i'm able to LOAD DATA in IRIS from a rather complex, say Oracle's, query. It works pretty well but requires a target table created aforehand:

LOAD DATA FROM JDBC CONNECTION SOME_OTHER_SERVER QUERY 'complex query here' INTO TargetTable

is there a way to base such target table on the same query ? 
CREATE FOREIGN TABLE seems to require a column definition which I would prefer to be taken from the query
CREATE TABLE AS SELECT seems to be for local queries and other methods, like Linked Table Wizard or %SYSTEM.SQL.Schema.