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.

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

At the heart of IRIS and Cache is a very interesting database architecture that we, at M/Gateway Developments, refer to as "Global Storage". If you ever wanted to know more about the fundamentals and capabilities of this underlying database, you might want to read a major analysis we've put together:

https://github.com/robtweed/global_storage

Amongst other things you'll discover that:

8 4
2 501

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
0 493

For some years I missed being able to offer, to everybody interested in ObjectScript, a tutorial more or less complete, to start with ObjectScript. Something that could help more and make things easier to those new developers that come to our technology... something intermediate, halfway between the common "Hello World!", that doesn't really get you further, and the "Advanced Training", that is unaffordable because of lack of time,etc.

If there were something truly helpful not only as an introduction to the ecosystem, but as a starting point, as a boost, to really start to walk into ObjectScript and move forward by yourself... wouldn't that be awesome?

7 7
0 491

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:

0 6
0 475

We are constantly running into issues where there are billions of Orphaned messages in our system that cause problems, and we have to manually run a cleanup to fix performance issues.

In the following article about orphaned messages... https://community.intersystems.com/post/ensemble-orphaned-messages it mentions either programmatically eliminating the Orphaned messages or using a Utility like Demo.Util.CleanupSet in ENSDEMO.

0 6
1 454

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.

1 2
0 448
Question
Confused Developer · May 27, 2017
Insert SQL

I am inserting rows in a table. This table is appearing in all namespace as I did global mapping.

So once I run insert command from a method, it insert the rows. When I run the same insert command from other namespace, it replace the existing data in table.

Insert command is same in all namespace but the data I m inserting is different.

0 2
0 439

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...

3 5
0 436

Hello. When you export and then import a table of data, is the import smart enough to figure out if a row already exists in the new namespace, and if so update the row rather than just save/add the row?

For example, we have a table in DEV, and the same table in QA. The DEV table has more fields than QA. When we moved up the class, the field definitions went with the table into QA, so now the table definition is the same in both.

0 2
0 429

Hi,

We are using CACHE 2017.2.1, I would like to retrieve data from Journal for killed global. Let say we have global name ^ EMP(123) with data and also have some child nodes and it has been killed by using cache kill command for some reason and we don't know who has executed this and when. My questions are below.

1) Can we get back the data of killed global from journal files,Is it possible or not ?

0 5
0 426

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

As you know in Caché / IRIS you have the possibility to define a property as Multidimensional as documented here:
https://docs.intersystems.com/iris20201/csp/docbook/DocBook.UI.Page.cls?KEY=GOBJ_proplit#GOBJ_proplit_multidim
and the explanation of how to use it
https://docs.intersystems.com/iris20201/csp/docbook/Doc.View.cls?KEY=GOBJ_proplit#GOBJ_proplit_multidim_values

Though the access is quite comfortable (in traditional COS sense) there are 2 main restrictions that hurt:

#1) It is not saved to disk unless your application includes code to save it specifically.
#2) It cannot be stored in or exposed through SQL tables
there are some more
I'll show how to overcome these limits

14 1
2 419

If you define a Persistent Class / Table the class compiler generates for you an appropriate Storage definition.
A different option is to define a SQL mapping for an already existing Global storage. This has been excellently
explained already in a different series of articles. The Art of Mapping Globals to Classes 1 of 3

10 7
1 401

Currently, namespace Alpha is configured to use database AlphaDB as its global database. How would we go about having namespace Alpha configured to use database AlphaDB for its global database except where global ^Customers(CustomerId) has a CustomerId greater than 10M, which we would like to have it redirected to database BetaDB.

In other words, ^|"AlphaDB"|Customers contains all customers between 1 and 10,000,000; and ^|"BetaDB"|Customers contains all customers greater than 10,000,000. Any help would be appreciated.

0 4
0 395