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#Globals

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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
· Apr 4, 2022 12m read
Store Mindmaps using Globals

Globals are the core of the InterSystems IRIS for data persistence. It is flexible, allowing store JSON documents, relational data, object oriented data, OLAP cubes and custom data models, like Mindmaps. To see how to store, delete and get mindmap data using globals, follow these steps:

1. Clone/git pull the repo into any local directory

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Article
· Jan 24, 2022 1m read
GlobalToJSON-Compact

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. Compact refers to the structure created.
Globals nodes are included with data for a fast data load.
But also the related code is quite compact.

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Article
· Jan 24, 2022 2m read
GlobalToJSON-Efficient

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.

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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
model.

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Article
· 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:

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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:

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Hi,

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

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

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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 :

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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:

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Introduction

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.

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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"

etc...

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Question
· 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:

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