New post

#Globals

8

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.

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:

0 36
0 702

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.

1 20
0 728

Hi all,

I am trying to create a method to count the number of entries in a global, including all subscripts. I am having a bit of trouble getting the code to make it to the second subscript. When I get to the position where my key is "Canada" and I add a comma and empty quotes to it, it returns USA as the new key when I do the order function. Is the $Order or the global not able to use a single string to represent multiple subscripts?

Here is my global structure:

2 20
0 492

Hi Developers!

Often we need to use relatively small arrays with constants, static arrays in algorithms, etc where we need to do something with each element of an array. There are several ways to deal with it in ObjectSctipt.

Previously I used to use globals, locals, PPG for this but not so long time ago figured out that %List is a way too handy.

Indeed, suppose we have an array of months and need to set up and use it in our code.

2 15
1 510

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
0 360
Question
Peter Stordiau · Feb 20, 2022
Maximum Global Size ?

Dear people,

I (really) spent hours on finding the maximum size a Global is allowed to be (for Windows, if that matters). All I seem to run into are database sizes (derived from a max number of blocks and block size), but I refuse to believe that is correct because too small to be realistic. surprise

1 11
0 359

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 :)

0 11
0 627

Globals, these magic swords for storing data, have been around for a while, but not many people can use them efficiently or know about this super-weapon altogether.

If you use globals for tasks where they truly shine, the results may be amazing, either in terms of increased performance or dramatic simplification of the overall solution (1, 2).

Globals offer a special way of storing and processing data, which is completely different from SQL tables. They were first introduced in 1966 in the M(UMPS) programming language, which was initially used in medical databases. It is still used in the same way, but has also been adopted by some other industries where reliability and high performance are top priorities: finance, trading, etc.

Later M(UMPS) evolved into Caché ObjectScript (COS). COS was developed by InterSystems as a superset of M. The original language is still accepted by developers' community and alive in a few implementations. There are several signs of activity around the web: MUMPS Google group, Mumps User's group), effective ISO Standard, etc.

Modern global based DBMS supports transactions, journaling, replication, partitioning. It means that they can be used for building modern, reliable and fast distributed systems.

Globals do not restrict you to the boundaries of the relational model. They give you the freedom of creating data structures optimized for particular tasks. For many applications reasonable use of globals can be a real silver bullet offering speeds that developers of conventional relational applications can only dream of.

Globals as a method of storing data can be used in many modern programming languages, both high- and low-level. Therefore, this article will focus specifically on globals and not the language they once came from.

14 10
0 2,135

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.

4 10
1 419

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
0 274

Hey InterSystems Community!

This is probably far-fetched - is there a way to get notified/get a piece of code triggered whenever the state of a global changes?

Now what could I possibly want with that? Quite simple! I would like to forward the content of a global (in this case the "FSLog" global written by the FHIR implementation) while adding timestamps to it - to create some sort of file-based logging for it.

0 9
0 195
Article
Alexey Maslov · 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 1,179

Hello All,

I have a class method on the DocRepo server that needs to query the data value of a global variable on the Edge server.

I have looked at the documentation for 'Global Structure,' but I didn't find anything that helped.

Global Structure | Using Globals | InterSystems IRIS Data Platform 2022.1

I am able to access this global easily from the Edge server using the $Get function, but I need to access it from the DocRepo server.

0 8
0 244

Currently, we have an application running in one namespace ("Database B") that has globals and routines mapped to another database ("Database A"). After enforcing clean up on Database A, we found that 90% of the disk is free. We would like to compact Database A and release the unused space. However, we are running OpenVMS, which seems to be the issue.

For databases consisting of only globals, we are able to use ^GBLOCKCOPY; however, we need to ensure that the routines and mappings are also copied.

1 8
0 885