While the integrity of Caché and InterSystems IRIS databases is completely protected from the consequences of system failure, physical storage devices do fail in ways that corrupt the data they store. For that reason, many sites choose to run regular database integrity checks, particularly in coordination with backups to validate that a given backup could be relied upon in a disaster.

This is the first article in a series discussing how to regain disk space from Caché databases at the operating system level. This introductory article discusses Caché database growth and gives an overview of various methods you can use to return unused disk space that is allocated to database files back to the file system. But before we talk about returning space to the file system, let’s first review how does it get allocated in the first place.

This article explains the basics of OpenVMS file structures, from a Caché prospective, and what you need to know to read and write any OpenVMS file with Caché, even the files with difficult file structures.

Index to Articles

Hi All

I am an avid user of ZEN for over 10 years now and it works for me.
But it seems that Intersystems are no longer actively developing it (or ZEN Mojo), the only published reference to this is here

C:\data\backup.bat :

C:\InterSystems\Ensemble\bin\cache -s"C:\InterSystems\Ensemble\Mgr" -U%%SYS ##Class(Backup.General).ExternalFreeze() <C:\data\login.scr

echo %ERRORLEVEL%

rem note that we need to check errorlevel from highest to lowest here....

if errorlevel 5 goto OK

If you want to dynamically serve images as a property of JSON then there is no perfect encoding solution. One method used frequently is to Base64 encode the image. Whilst there are some negatives to doing this, such as data inflation, there are some positives to working with Base64 images inside the browser.

Let's say you have an image placeholder on a web page...

The technology of load balancing between several servers with relatively low capacity has been a standard feature of Caché for quite a while. It is based on the distributed cache technology called ECP (Enterprise Cache Protocol). ECP provides a host of possibilities for horizontal scaling of an application, and yet keeping the project budget fairly low. Another apparent advantage of ECP network is the possibility to conceal its architecture in the depths of Caché configuration so that applications developed for the traditional (vertical) architecture can be fairly easily migrated to a horizontal ECP environment. The ease of this process is so mesmerizing, that you start wishing it was always this way. For instance, everybody is used to having a possibility to control Caché processes: the $Job system variable and associated classes/functions work magic in skilful hands. Stop, but now processes can end up being on different Caché servers…

This article is about how to gain as much transparency in controlling processes in ECP environment as in traditional (non ECP) one.

(Originally posted on Intersystems CODE by @Eduard Lebedyuk, 10/12/15) The following code snippet outputs all filenames in the file path "dir" in the Cache/IRIS terminal. The class method "test" runs the code:

Class eduardlebedyuk.filenamesInDir Extends %RegisteredObject
{
	classmethod test() {
		// replace dir with file path you want
		set dir = "D:\directory" 
		set dir = ##class(%File).NormalizeDirectory(dir)
		set file=$ZSEARCH(dir_"*")
		while file'="" {
			write !,file
			set file=$ZSEARCH("")
		}
	}
}

Several years ago everyone got mad about BigData – nobody knew when smallish data will become BIGDATA, but all knows that it’s trendy and the way to go.

Question

I am configuring IIS to work with the CSP Gateway but I'm running into this error:

"The Module DLL 'C:\Inetpub\CSPGateway\CSPms.dll' could not be loaded due to a configuration problem. The current configuration only supports loading images built for a x86 processor architecture."

Answer

We finished our last lesson with our Widgets Direct page receiving a Welcome message as a property of a JSON object, which was unpacked and displayed on the page. However, we are on Lesson 3, and we still haven't had any talk of displaying widgets yet.

In this article we are going to compare $Increment and $Sequence functions.

Beginning - see Part 1.

3. Variants of structures when using globals

A structure, such as an ordered tree, has various special cases. Let's take a look at those that have practical value for working with globals.

3.1 Special case 1. One node without branches

Overview

Encryption of sensitive data becomes more and more important for applications. For example patient names, SSN, address-data or credit card-numbers etc..

Cache supports different flavors of encryption. Block-level database encryption and data-element encryption. The block-level database encryption protects an entire database. The decryption/encryption is done when a block is written/read to or from the database and has very little impact on the performance.

With data-element encryption only certain data-fields are encrypted. Fields that contain sensitive data like patient data or credit-card numbers. Data-element encryption is also useful if a re-encryption is required periodically. With data-element encryption it is the responsibility of the application to encrypt/decrypt the data.

Both encryption methods leverage the managed key encryption infrastructure of Caché.

The following article describes a sample use-case where data-element encryption is used to encrypt person data.

But what if you have hundreds of thousands of records with an encrypted datafield and you have the need to search that field? Decryption of the field-values prior to the search is not an option. What about indices?

This article describes a possible solution and develops step-by-step a small example how you can use SQL and indices to search encrypted fields.