#Object Data Model

InterSystems FAQ rubric

Information on properties defined in a class can be obtained using the following system classes:

%Dictionary.ClassDefinetion

Quotes (1NF/2NF/3NF)^ru:

Every row-and-column intersection contains exactly one value from the applicable domain (and nothing else).
The same value can be atomic or non-atomic depending on the purpose of this value. For example, “4286” can be

• atomic, if its denotes “a credit card’s PIN code” (if it’s broken down or reshuffled, it is of no use any longer)
• non-atomic, if it’s just a “sequence of numbers” (the value still makes sense if broken down into several parts or reshuffled)

This article explores the standard methods of increasing the performance of SQL queries involving the following types of fields: string, date, simple list (in the $LB format), "list of <...>" and "array of <...>".

This article was written as an attempt to share the experience of installing the InterSystems Caché DBMS for production environment.
We all know that the development configuration of a DBMS is very different from real-life conditions.
As a rule, development is carried out in “hothouse conditions” with a bare minimum of security measures, but when we publish our project online, we must ensure its reliable and uninterrupted operation in a very aggressive environment.

I recently met an ages old issue related to code maintenance:

• You have access to your IRIS server just over ODBC/JDBC
• no VSCode access, no Studio access
• no (Web-)Terminal access

But you need to take a look on Classes or Routines or Globals !!
Anyhow SQL is your friend.

Here's one way to determine if a class is mapped (i.e. it is in a package whose definitions come from a database other than the default code database for the current namespace):

SAMPLES>w ##class(%Library.RoutineMgr).IsMapped("Cinema.Film.cls")
0
SAMPLES>w ##class(%Library.RoutineMgr).IsMapped("%iKnow.Objects.Source.cls")
1
SAMPLES>

If you pass a by-ref second argument to IsMapped you can also discover what database the class definition is stored in:

Here you have an easy way to write and execute COS code from your unix scripts. This way one does not need to write routines or even open Studio or Atelier. It can be an option for simple and small actions for instance things like installation tasks or compiling.

See sample bash script (compile.sh) to compile classes:

Columnar storage is one of the newer offers provided by InterSystems IRIS. Unlike traditional row-based storage, it optimizes query processing by storing data in columns rather than rows, enabling faster access and retrieval of relevant information.

A couple of articles have been written on when it should be used to give a system the biggest boost, how to create tables like that using SQL

CREATE TABLE table (column1 type1, column2 type2, column3 type3) WITH STORAGETYPE = COLUMNAR  -- ex 1
CREATE TABLE table (column1 type1, column2 type2, column3 type3 WITH STORAGETYPE = COLUMNAR)  -- ex 2

and even the performance tests.

As we all know, InterSystems IRIS is a multi-model DBMS and it gives seamless access to the same data using relational and object access. So the former is covered in other articles, but what about the latter?

I'd like to announce the release of something really rather interesting - revolutionary in fact. That may sound like hyperbole, but I don't think you'll have seen anything quite like this, or even thought it possible!

We've pushed out a new JavaScript/Node.js module named glsdb which you can read all about here in detail:

https://github.com/robtweed/glsdb

Today, I was reading some source code, and encountered the following method signature:

Method SendRequestSync(pRequest As %Library.Persistent, ByRef pResponse As %Library.Persistent)

And I immediately thought, why is there a ByRef?

Object Synchronization is a feature that has been around for a while, since Caché days, but I wanted to explore a bit more how it works. I've always thought that database automatic synchronization is complex by nature but, for some particular scenarios shouldn't be so hard. So I considered a very simple use case (OK, perhaps the typical one, I'm not discovering anything... but if it's common and it works, it's good ).

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.

Greetings! This article describes yet another simple way of creating installers for the solutions based on InterSystems Caché. The topic covers applications, which can be installed or completely removed from Caché with one action only. If you are still documenting installation instructions that have more than one step to do to install your application — it’s high time you automated this process.

Often when debugging COS code you get an error message such as '<UNDEFINED>test^routine *test' so the first thing you want to do is to take a look at this code and see what it is doing. From the command line you can:

In part I of this series we have introduced MapReduce as a generic concept, and in part II we started to approach Caché ObjectScript implementation via introducing abstract interfaces. Now we will try to provide more concrete examples of applications using MapReduce.