#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 Eduard Lebedyuk · Jul 16, 2019 4m read

When I describe InterSystems IRIS to more technically-minded people, I always start with how it is a multimodel DBMS at its core.

In my opinion that is its main advantage (on the DBMS side). And the data is stored only once. You just choose the access API you want to use.

  • You want some sort of summary for your data? Use SQL!
  • Do you want to work extensively with one record? Use objects!
  • Want to access or set one value and you know the key? Use globals!
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Question Frank Langel · Mar 15, 2020

    Hi, 

   I  like to validate some use cases and have the following question. I am relatively new to IRIS. Perhaps someone can help:

   1. I have a global m[x,y,z,f] distributed across multiple sharded instances
   2. I know that i can set assign computed SQL expressions to class variables using Objectscript 
   3. Is there a possibility in Globals API to do the same ? Set f = x + y as a computed expression in the global  m[x,y,z,f]  ?

       a.  We would want to use the global API to change f programmatically using code

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Discussion Evgeny Shvarov · Aug 31, 2019

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.

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Article Sergey Kamenev · Nov 11, 2019 11m read

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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Question Robert Hanna · Aug 23, 2019

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:

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Discussion Evgeny Shvarov · Aug 18, 2019

Hi Developers!

InterSystems IRIS stores everything in globals and if we use ObjectScript classes to persist data class documents globals it uses in storage. But if you use globals for calculations, temporary storages, for special indexes or for some other purposes - how do you document it?

Possible options which come to my mind:

1. Macro

#define Array ^MyGlobal

usage:

s $$$Array(1)=1

2. Class parameter

Parameter Array ="^MyGlobal";

Usage:

s @(..#Array)@(1)=1

3. Documentation comment

Just document it to have it in a class documentation

/// ^MyGlobal is used to store my data

What do you do?

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Question nok nok · Jul 17, 2019

Hi there

Would you please advise how to count how many keys are duplicated in global, for example, Athens was duplicate 3.

Set ^Data("Cambridge") = "1"
 Set ^Data("New York") = "2"
 Set ^Data("Boston") = "3"
 Set ^Data("London") = "4"
 Set ^Data("Athens") = "5"
 Set ^Data("Athens") = "6"
 Set ^Data("Athens") = "7"

Thanks

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Question Jeffrey Drumm · Jul 18, 2019

I need to copy a bunch of globals from some crufty old databases to spanking clean brand new ones. GBLOCKCOPY has this cool feature that lets you create a batch of global names to copy and save the list in a batch. You can then execute the batch and go take a nap.

I like naps.

I need to do this for a number of old-new database pairs, but it's the same global names every time. Is there a way to export the batch configuration created the first time and import it to another environment/namespace? These databases will be spread across multiple hosts.

Thanks!

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Article Sergey Kamenev · Jul 7, 2017 7m read

In the previous parts (1, 2) we talked about globals as trees. In this article, we will look at them as sparse arrays.

A sparse array - is a type of array where most values assume an identical value.

In practice, you will often see sparse arrays so huge that there is no point in occupying memory with identical elements. Therefore, it makes sense to organize sparse arrays in such a way that memory is not wasted on storing duplicate values.

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Question Alexey Maslov · Jan 31, 2019

Sometimes global mapping of the same globals can be defined in different ways. E.g., I need to define it for 3 globals ^qAuditC, ^qAuditLog, ^qAuditLogC from the same database named APP-NOJOURN. Which approach should be better from the performance point of view?

1) qAudit* => APP-NOJOURN (one record in global mapping table)
or

2) qAuditC => APP-NOJOURN
qAuditLog => APP-NOJOURN
qAuditLogC => APP-NOJOURN (three records in global mapping table)

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Question Sergio Martinez · Feb 12, 2019

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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Article Alexey Maslov · Nov 23, 2017 12m read

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:

  • We can't export such a global using Caché Block format (a.k.a. GOF).
  • We can't kill such a global.

Maybe you can continue this list.

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Question Kurro Lopez · Sep 13, 2018

Hi,

I've read into console.log that there is some problems writing the global Task History

09/13/18-09:33:00:109 (9052) 0 Error al escribir en global de historial de tareas - Error (ERROR #5002: Error de cache: <DATABASE>%SaveData+20^%SYS.Task.History.1 ^SYS("Task","HistoryD",66179),c:\intersystems\healthshare\mgr\)
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Question Alexey Maslov · Jun 7, 2018

I'm working on a task where I need to apply journal file records to another database. I can't use Journal.Restore class methods as I need to perform some data transformation, therefore I'm reading journal file record by record using %SYS.Journal.Record API.  

It seems that there are only few journal records that I need to process, namely:

Type TypeName
6    SET
7    KILL
8    KILLdes
9    ZKILL
10   RemoteSET
11   RemoteKILL
12   RemoteZKILL
14   BitSET

No problem, while I'm just curious: which COS command could provide KILLdes record? I've met it only once in the context like this:

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Question Antonio Garcia Martinez · May 10, 2018

Hi,

I wonder if you could help me with a problem with persistent globals and journals.

We have a few interfaces using a persistent global just to translate some codes. The use of that global is like a lookup table...an interface calls a method that search for a field (in the message) in the global. If found, the code is translated with another field from the global.

The format of the global is something like:

$LB("","1","2","3","4","5","6","7","8","9","10","11","12","13","14","15","16","17","18","19","20","21","22","23","24","25","26","27")
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Question Joan Cruz · May 3, 2018

Hi,

I'm trying to export a global with this library %Library.Global with this call:

Do ##class(%Library.Global).Export(pstrNamespace, pstrGlobalName, pstrOutputPath,,,"-d")

When I call this method $ZERROR is setted to "<NOTOPEN>OpenDev+15^%Wprim"

Can someone tell me where is the problem on this?

Thanks a lot

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Question Георгий Самаров · Apr 27, 2018

Hi! I have a local project written on Cache and Atelier on my PC. I need to move it to notebook. Tried to export globals, classes, MAC-programms and csp with frontend stuff, but after I created my apps on notebook and imported my set, it just didn't work. I think it's because I have some settings on Management Portal, so how can I export portal settings and what I should export to have my working apps on another computer?

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Question Bob Felbol · Apr 4, 2018

Hi.

The message is received a few times a day.

On documentation, this ^ISCSOAP^is log to service SOAP, but why send to cconsole.log?

04/04/18-01:00:00:597 (10608) 2 ^ISCSOAP in Namespace %SYS has been active for 348 day(s).
04/04/18-01:00:00:598 (10608) 2 ^ISCSOAP in Namespace X has been active for 165 day(s).

Help-me.

Tks

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