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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In this article you will have access to the curated base of articles from the InterSystems Developer Community of the most relevant topics to learning InterSystems IRIS. Find top published articles ranked by Machine Learning, Embedded Python, JSON, API and REST Applications, Manage and Configure InterSystems Environments, Docker and Cloud, VSCode, SQL, Analytics/BI, Globals, Security, DevOps, Interoperability, Native API. Learn and Enjoy!

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Suppose we need to store millions of values temporarily, that means, we don't care about them if we lose them but our application use them to get realtime information. Should I use Cachetemp or whatever other DB without journaling enabled? If answer is Cachetemp, shouldn't be a problem if we decide to scale using App Server + ECP? I'm not sure what would happen with the app logic in such architecture as I guess I couldn't map and share cachetemp...

Any idea/suggestion?

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Question
· Nov 4, 2020
Avoid $c(0) in globals

Good Morning,

I have this question for a long time. When I make an insert by SQL from an external application in the fields of type %String, if they are empty, it writes the character $c(0) in the global.

Is there a way so that if an Insert is received in a field of type% String with null value instead of the $ c (0) it leaves it empty?:

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Hi, Community!

Is there an option to get an archived file of globals in one command. Say for:

Do $System.OBJ.Export("Class1*D.GBL,Class2*D.GBL","data_gbl.xml")

get something like:

Do $System.OBJ.Export("Data*D.GBL","data_gbl.gz","gzip")

And also to have the convenient one click way to import it to the namespace via terminal or Control Panel?

If anyone already has this module, share please?

It would be very convenient for import/export/continuous integration purposes cause globals can be really heavy.

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Is there a way to omit or skip rollback of some data changes during a transaction rollback? Maybe some sort of "autonomous transaction"?

The issue is with error logging in transaction. For example we may have in nested calls the following structure:
TS
<some code>
<error happens>
TRO 1
<error log to database>

but if this code is in another transaction, and that rolls back we lose error data.

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Article
· Nov 11, 2019 11m read
Transactions in Global InterSystems IRIS

InterSystems IRIS supports a unique data structure, called globals, for information storage. Essentially, globals are persistent arrays with multi-level indices, having several extra capabilities—transactions, quick traversal of tree structures, and a programming language known as ObjectScript.

I'd note that for the remainder of the article, or at least the code samples, we'll assume you have familiarised yourself with the basics of globals:

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I have a simple app which tries to establish a connection with a Cache database instance via Global API for Java:

import com.intersys.globals.Connection;
import com.intersys.globals.ConnectionContext;

public class Assignment {

    public static void main(String[] args) {
        Connection connection = ConnectionContext.getConnection();
        connection.connect("SAMPLES", "_SYSTEM", "SYS");
    }

}

The expection I am getting:

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NewBie's Corner Session 27 Traversing A Global with $Order Part 1

Welcome to NewBie's Corner, a weekly or biweekly post covering basic Caché Material.

Traversing A Global

Perhaps the most difficult concept in Caché/MUMPS is its Global Structure. This session and several that follow it deals with the Global Structure. However, just presenting the material will not guarantee your understanding of it. You must experiment with the data and concepts that are presented.

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Article
· Aug 8, 2017 1m read
Outperforming PostgreSQL and MySQL

In a previous exercise, I was able to show the power of Caché.
A medium-designed set of interdependent tables with some GB of data.
URLs cross reference over some million pages resulting in ~3 billion records

Competition was between

  • Caché
  • PostgreSQL
  • MySQL

Criteria were Speed + Storage consumption
I composed a customized loader fed over a "raw" TCP connection
Mapping the "objects" into the final table by directly writing to Global Storage.,

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Can someone direct me to where in the documentation we can find how consumption may be calculated for global storage?

Caché Version2010.1
Operating SystemHP OpenVMS 8.4

EDIT: After receiving some responses, it seems I was unclear in my initial inquiry. I am looking to determine our rate of consumption of storage; however, I am having some difficulty in doing that.

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A More Industrial-Looking Global Storage Scheme

In the first article in this series, we looked at the entity–attribute–value (EAV) model in relational databases, and took a look at the pros and cons of storing those entities, attributes and values in tables. We learned that, despite the benefits of this approach in terms of flexibility, there are some real disadvantages, in particular a basic mismatch between the logical structure of the data and its physical storage, which causes various difficulties.

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Hi,

I have a class with around 400k lines and 60 columns. Class storage is Cache SQL storage (Mapped from a global).

I want to create multiple indices on certain fields.

I am familiar with two approaches:

1. Create a new map (Index type) on a pointer global.

2. Create a bitmap index

Which approach is more recommended to be used in the case I described? If there are any other approaches, I will be happy to hear.

Thanks :)

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Have very little XML experience and have been able to manually create output. Have a need to take data that I store in a M global (example: ^TML("HDATA", ) and out put it in CCDA XML format.

Are there any examples of M code using the XMLWriter to accomplish this?

Or can anyone provide some guidance

Any help would be greatly appreciated.

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Hello community!

I'm facing a base growth issue, which is being generated by a process and an Ensemble feature.

When executing the process of cleaning up the message queues, the Ensemble “preserves” the Streams that were part of these messages, deleting only the Header and Body. In this way the database (of one of the namespaces) has grown around 60GB per day, which has been maxing out the disk capacity.

InterSystems informed that this is a characteristic and that it is explained in the documents mentioned below.

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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):

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