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.

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Article
· Jul 26, 2017 3m read
What is APM?

What is APM?

I am talking about Application Performance Management at global summit, and several people have asked what that means so it is time for a bit of an explanation.

APM or Application Performance Management (sometimes referred to as Application Performance Monitoring) has a very good (if complicated) explanation on Wikipedia but to me it just means looking at performance from the users’ point of view and the level of service provided to them.

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Question
· Jul 26, 2017
Crystal_Report with Caché

Hi All,
I tried to connect Crystal report with Cache 5.0 Its Show Crystal Report error as "The report you requested requires further information."
How to resolve the issue in C#.

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Question
· Jul 25, 2017
[Fixed]Error with ECP

Hello,

I try to create an ECP between to CACHE server.

The ECP is working, the remote DB is created and the namespace is created and linked on the remote DB.

The table appears on the server but when I try to access I get this message:

ERREUR #5540: SQLCODE : Message 400 : Process 4076 failed to compile Cached Query Class %sqlcq.###.cls6 with these errors: ERREUR #5002: Erreur Cache: <COLLATION NOT SUPPORTED>getdependencyclasses+54^%occDepend SQLTEXT: SELECT ...

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Article
· Oct 18, 2016 7m read
Macros in the InterSystems Caché

In this article I would like to tell you about macros in InterSystems Caché. A macro is a symbolic name that is replaced with a set of instructions during compilation. A macro can “unfold” in various instruction sets each time it is called, depending on the parameters passed to it and activated scenarios. This can be both static code and the result of ObjectScript execution. Let's take a look at how you can use them in your application.

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Article
· Sep 2, 2016 2m read
Advanced URL mapping for REST

By now it's a commonplace how to implement a basic REST API in Caché and there is good documentation about it here: REST in Caché

A question that comes up from time to time is:

How can I make a parameter in my REST url optional?

Simply put, is it possible to create a URL map in Caché that maps a URL like this:

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Question
· Jul 18, 2017
how to release memory for process?

hi

I query large mount of rows from one table with JDBC, and will prompt <store> error. I found that it was out of process memory (default 16M, max 49M in version 2010.2) .

so my question is : how to release memory for large mount of rows query? or how to resolve this error?

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Question
· Jul 21, 2017
how to redirect IO

I get a third party routine which outputs some messages to standard output during execution.

Is it possible that I could direct the messages to other device so my terminal would never see this messages?

Thanks.

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Question
· Jul 20, 2017
Cursor placement

Greetings,

What methods are available to position a cursor on a screen to begin writing as not to disrupt other areas of the screen? I have used ?# , ie: ?5 but this is destructive from the let to character 5. I would like to enter a command that will position at row,col and then start writing? Can I create a window in a window type display to write text and then when done viewing, remove it?

Please advise,

Thanks in advance for everyone's time.

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I have a query string that I am creating programmatically, based on some user inputs. The user might search on 5 fields, or 8 fields, or no fields.

In my sql statment, some of these fields require parameters in the %Execute statement.

For example:

if user picks lastname, sql = "select * from person where lastname = ?"

if user also picks age, sql = "select * from person where lastname=? and age > ?"

I then have these lines of code to create my result set:

set statement = %SQL.Statement

statement.%Prepare

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Hi Community!

Please find the Developer Community video of the week on the InterSystems Developers YouTube Channel:

Upgrades - Minimizing Business Disruption

https://www.youtube.com/embed/CrY-vPVcJdM
[This is an embedded link, but you cannot view embedded content directly on the site because you have declined the cookies necessary to access it. To view embedded content, you would need to accept all cookies in your Cookies Settings]

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Hi,

Is it possible to use the value of a column that is populated by its own subquery, in the WHERE clause of the outer-query ?

The following fails (it does not parse syntactically):

SELECT A, B, (SELECT S1 FROM Table2) "C" FROM Table1 WHERE C>10

I guess I could wrap it up as in inner query of it's own - this way (which works) :

Select * from 
(SELECT A, B, (SELECT S1 FROM Table2) "C" FROM Table1)
where C>10

but I was wondering if there was some syntax in the original snippet that I could do instead.

Thanks - Steve

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Hello! So, my knowledge on the Cache database is extremely limited, and I was hoping I could find some assistance here. I'm connecting to the DB via ODBC. The table(s) I'm interested in are named as such nameYYYYMMDD. So each day, a new table is created with logs. We'd like to grab these records each day, for the previous day's logs.

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Hi all,

I was wondering if there is any way to trigger the compilation of a class based on the compilation of another (unrelated) class. For example:

Class 1 = test.class

Class 2 = test.class.type.one

Class 3 = test.class.type.two

Every time class 2 or class 3 is compiled in Studio I would like to have class 1 automatically compiled as well.

The reason I need this is because class 1 has a method with CodeMode set to objectgenerator which generates some code based on what is found in classes 2 and 3.

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Below are the output messages when Cache start.

Allocated 178MB shared memory: 1MB global buffers, 26MB routine buffers

I try to configure the global buffer size by [System] -> [Configuration] -> [Memory and Startup] from SMP,

but it seems like the changes does not apply to the global buffer.

Thanks for your help.

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Question
· Jul 10, 2017
How to encrypt column value in sql?

hi

I want to update some columns in one table like this:

    update table1 set col1=%SYSTEM.Encryption_AESCBCEncrypt(col1, 'key')

but the error is

ERROR #5540: SQLCODE: -359 Message: User defined SQL Function '%SYSTEM.ENCRYPTION_AESCBCENCRYPT' does not exist

what's the corect syntax? Thanks!

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Hi,

I have a situation where I write a character stream to a file. The file content gets signed and the signature is sent to a service provider together with the file content.

The signing is done using openssl.

This works perfectly on a dev PC, which is runnning Windows and has a little-endian architecture.

The problem is as soon as I do this on the server, which has a big-endian architecture, the signed value is incorrect according to the service provider.

The content is signed using RSA SHA256 with PSS padding.

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Greetings,

If given a global, how can I discover information on that global? More specifically, how can I discover how many indices it contains? ie: ^G(1,2,3,4,5) How can I discover that there are 5 subscripts within the Global ^G if I did not already know.

Please advise, and thanks in advance for everyone's time.

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Hi everyone

Is there any way to change a class definition (especifically a query definition during the compilation time)?
The idea is:
I have an abstract class with a parameter where I will define the ROWSPEC of a query and some methods to populate e temporary table
The implementation class will override the parameter, specifying the ROWSPEC of this implementation, and the methods will populate the rows in the same format as the ROWSPEC.

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