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.

5 13
1 615

JSON is a lightweight data interchange format for 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:

5 1
2 163
· Jan 24, 2022 2m read

I have created a package that offers a utility to load a Global into JSON object and reverse
to create a Global from this type of JSON object. Efficient refers to the structure created.
Only Globals nodes containing data are presented in the generated JSON object.

4 2
0 323
· Nov 23, 2017 12m read
Where is my global stored?

It's well-known that namespace global mapping helps us to write code independent on database storage details (Caché instance name, directory path). But sometimes we can face problems accessing an unsubscripted global which has subscript level mapping (SLM) defined. Most of such cases are evident and associated with administrative tasks that should be done on database level, but some of them can confuse even an experienced developer. Just to start:

4 8
0 1.3K

Making a blog using Python + IRIS Globals

Since I started to use internet (late 90's), I always had a CMS (content management system) present to make easier post
any information in a blog, social media or even an enterprise page. And later years putting all my code into github I
used to document it on a markdown file. Observing how easy could be persisting data into Intersystems IRIS with the
Native API I decided to make this application and force myself to forget a little of SQL and stay open to key-value database

4 2
0 351

Process-private Globals can be used as a data global in storage definition. That way, each process can have its own objects for the class with ppg storage. For example lets define a pool, which can:

  • add elements to a pool (ignoring duplicates)
  • check if an element exists in the pool

Here's the class:

4 2
0 899


In the first article in this series, we’ll take a look at the entity–attribute–value (EAV) model in relational databases to see how it’s used and what it’s good for. Then we'll compare the EAV model concepts to globals.

3 0
4 3.6K

Hi developers!

As you probably noticed in IRIS 2021 the names of globals are random.

And if you create IRIS classes with DDL and want to be sure what global was created you probably would want to provide a name.

And indeed you can do it.

Use WITH %CLASSPARAMETER DEFAULTGLOBAL='^GLobalName' in CREATE Table to make it work. Documentation. See the example below:

3 11
0 501

If I were trying to access an index of a global variable, what time complexity would this operation have? My understanding of languages like Java/C++ is that arrays are stored as blocks of memory so that x[15] would have a lookup time complexity of O(1) because it just goes to (address of the array + 15) and retrieves the value stored there.

How does this work in Cache where the index of a variable isn't necessarily an integer value? If I were to have a variable like the following:

x("Adam") = "Red"

x("George") = "Blue"

x("Bryan") = "Green"


3 5
0 499

Let's consider you would like to efficiently store your historical data in a similar structure than the one used for your current data, but without sharing the same physical storage (ie : not in the same global). What is the most efficient way to do it ?

Below a simple class of your current data :

3 9
0 363

I have created a global say ^myglobal and entered some data. I am storing the name of global in databases and fetching the name based on some criteria. I am getting "^myglobal" in return from databases but i am not able to fetch the data I stored in the global.

I tried set var = which gives me "^myglobal" in var. Doing WRITE var will return "^myglobal" and not the data i stored in this global.

3 5
1 270


We have a global with 65 million entries. All we are doing is just iterating through each entry to find out the total no of entries. It is currently taking 110 minutes. Is this something normal? What can we do to speed up this process? Below is the program for just iterating each entry in the global.

s sub=" ,count=0
s sub=$o(^YYY(sub)) q:sub=""
s count= count +1
w!, "Total Count:"_ count

3 19
1 442
· Jan 24, 2022 1m read

I have created a package that offers a utility to load a Global into JSON object and reverse
to create a Global from this type of JSON object. Academic refers to the structure created.
Each logical node of the Global is presented separately with all its descendants.
Even if they don't contain any stored data.

2 1
0 272

This example demonstrates the difference you may experience when you write to
Gllobals directly from Embedded Python compared to native ObjectScript.

To make this demo useful I start 2 background jobs that simply write sequentially
to a dedicated global. A common control method signals for a synchronous start.
Similar a common stop & view interrupts data feeding.

That's the principle process:

2 1
0 218
· Mar 17, 2023
A confusing experience

During my last migration to IRIS I met this Compatibility parameter

  • NullSubscripts true
0 - Throw error when referencing a null subscript.
1 - Null subscript references do not throw an error.

The consequences are shocking. This was allowed:

2 5
0 293

We're developing Ensemble PoC and one day our frontend developer (who doesn't have Ensemble production running) said that Populate just doesn't cut it and he needs to see the real data. He needed only one object, but the problem was - it's a big object. Still, I checked ids of everything related and wrote this command (parts omitted, but you get the idea):

2 1
0 665