Problem:

Caché prints to printers in a manner somewhat different from other Windows applications. Caché sends the data directly to the GDI Printer, without the usual interface. This is because the GUI interface can only be shown on a system desktop session and not in web browser and terminal sessions. Some printer drivers have problems with this method of printing.

Is this the problem you are having?

In the prior part of this series we have provided introduction to Google MapReduce approach, but still not covered their possible ObjectScript implementation. Which we will start to explain today.

The release of IBM POWER 8 processors with AIX 7.1 introduced up to 8 SMT threads per processor core (logical or physical). Which SMT level (1, 2, 4, or 8) to use can be confusing and varies based on multiple factors. This article is meant to help with a starting point for your specific application.

Firstly, if running on a version of 2014.x or older, it is advised to use SMT 4 or lower. SMT 8 with those older versions of Cache' has shown a decline in performance and scaling in benchmarking applications.

Process-private Globals can be used as a data global in storage definition. That way, each process can have its own objects for the class with ppg storage. For example lets define a pool, which can:

• add elements to a pool (ignoring duplicates)
• check if an element exists in the pool

Here's the class:

Recently I wrote about automatic removal of system methods from the codebase.

Today, I'm ready to present you a working solution (codename: SMR) for this task.

The attached file contains an example of code generation using ObjectGenerators which builds a very simple homemade RuleEngine.

Code generation is an excellent way of increasing performance moving run-time calculations to compile-time.

We could generate code creating routines or implemeting methods using ObjectGenerators. In this example we are using ObjectGenerators.

Update: Rule Engine is now on GitHub https://github.com/intersystems-ib/cache-iat-ruleengine

Imagine that your .NET project uses the Caché DBMS and you need a fully-functional and reliable authorization system. Writing such a system from scratch would not make much sense, and you will clearly want to use something that already exists in .NET, e.g. ASP.NET Identity. By default, however, this framework supports only its native DBMS – MS SQL. Our task was to create an adaptor that would let us quickly and easily port Identity to the InterSystems Caché DBMS. This work resulted in creation of the ASP.NET Identity Caché Provider.

What do you do if you want to have the ID field have a meaningful name for your application?

Sometimes it comes to pass that when you're making a new table that you want to have the unique row identifier (a.k.a. IDKEY) to be a field that has a name that is meaningful for your data. Moreover, sometimes you want to set this value directly. Caché fully supports this functionality and it works Suppose you have a class Test.Kyle. The data will be stored like so:

^Test.Kyle(IDKEY)=$LB("",Field1,Field2,...,Fieldn)

We are in the process of putting a new UI on the existing product documentation, including a mobile-optimized view. We also plan on releasing additional "solution based" documentation that is targeted at common usage scenarios or important configuration tasks.

We are interested in your feedback on our current product documentation - what you like and dislike and especially what changes you would expect to see to make it as useful as possible.

I am pleased to announce the next 2016.2 field test kit, 2016.2.0.609.0.

This is a relatively light update with only a few dozen changes from the previous field test, spread out across all areas of the product. Also, in a break from the recent past, this update doesn’t contain any new fixes to problems found in the field.

Please download the kit and give it a try; the latest field test of 2016.2 is available HERE. And, as always, we welcome your feedback.

Steve Glassman, Director of QD

I have seen a customer problem recently where the use of a virus scanner running over Caché databases was causing intermittent application slow downs and bad user response times.

This is a surprisingly common problem, so this short post is just a reminder to exclude key Caché components from your virus scanning.

Generally virus scanning must exclude the CACHE.DAT database files and Caché binaries. If an anti-virus is scanning CACHE.DATs and InterSystems files then system performance will be significantly impacted.

Development productivity? Isn’t it kind of an oxymoron? Anyhow, we all dream a magic tool which does the tedious job of the software development and leave the intuitive or creative part on the developer. Atelier is the next generation tool of InterSystems aiming to boost the productivity of Caché/ Ensemble based software development. Atelier is based on the popular Eclipse IDE platform, which makes available the “infinite” pool of third party tools for Caché developers. Those tools can truly boost the productivity. This short article gives some examples how third party plug-ins can help developing for Caché. It is an absolute beginner’s guide, beginner to Eclipse but experienced to Caché.

With the release of Cache 2016.1, JSON support was re-architected and made part of the core object model with the creation of %Object and %Array classes, which allow you to create dynamic JSON enabled objects and arrays.

On a recent demonstration I was working on, I had the need to create a REST web service that returned a JSON representation of a persistent object. After searching for methods that would allow me to accomplish this, ultimately I found none, until now.

Checking if Directory or File Exists:

Outlined below is an example of how to check if a directory exists:

Set directoryName="c:\temp\nosuchdir"

/* Check for existence of a directory - Return Value:  0 - directory does not exist;  1 - directory does exist  */

Set directoryExists=##class(%File).DirectoryExists(directoryName)

If ('directoryExists)  // do the processing for when a directory does not exist

Outlined below is an example of how to check if a file exists: