SQL

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When I start talking about InterSystems IRIS with more technically-minded people I always talk about how at the root of things it is a multimodel DBMS.

In my opinion that is the main advantage (on the DBMS side).

You want some sort of summary for your data? Use SQL!

Do you want to work extensively with one record? Use objects!

Want to access or set one value and you know the key? Think again. Use globals!

And the data is stored only once. You just choose the way you want to access it.

On the first overview it's a nice story - short and concise and it gets the message across, but when people really start working with InterSystems IRIS the questions start.

How are classes and tables and globals related? What are they to each other? How's data really stored?

In this article I would try to answer these questions and explain what's really going on.

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I am pleased to announce that Release Candidates of Caché and Ensemble 2017.2 are now available.

Many customers have already downloaded the Field Test over the past few months, and we appreciate your feedback.

This release contains significant improvements, including:

Last comment 10 October 2017
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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 <...>".

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The Data Platforms department here at InterSystems is gearing up for this year's crop of interns, and I for one am very excited to meet them all next week!

We've got folks from top technical colleges with diverse specialties from hard core engineers to pure computer scientists to mathematicians to business professionals. They come from countries around the world like Vietnam, China, and Finland and they all come with impressive backgrounds. We're sure they will do very well this summer.

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The Art of Mapping Globals to Classes (4 of 3)

The forth in the trilogy, anyone a Hitchhikers Guide to the Galaxy fan?

If you are looking to breathe new life into an old MUMPS application follow these steps to map your globals to classes and expose all that beautiful data to Objects and SQL.

If the above does not sound familiar to you please start at the beginning with the following:

The Art of Mapping Globals to Classes (1 of 3)

Last comment 12 June 2018
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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. 

Last comment 16 March 2017
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I've asked a lot of questions leading up to this, so I wanted to share some of my progress.

The blue line represents the number of messages processed.  The background color represents the average response time.  You can see ticks for each hour (and bigger ticks for each day).   Hovering over any point in the graph will show you the numbers for that period in time.

This is super useful for "at a glance" performance monitoring as well as establishing patterns in our utilization.

Last comment 4 November 2016
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Hello,

We are sometimes asked for examples of how to do 3rd party SQL database selects/updates/inserts/stored procedures from an Ensemble SQL Business Operation.

In the attached file there are 4 sample Ensemble Operations that demonstrate four different types of transactions with an external SQL DB:

Last comment 8 June 2016
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Hi Everyone!

New video, recorded by @Stefan Wittmann, is already on InterSystems Developers YouTube:

SQL and Object Access

 

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It is often necessary to sort the results of a query on a string field containing a combination of alphabetic and numeric characters. In cases like this the default string collation may not always return the data in the expected sequence.

 

An example of this may be where a select from Samples.Person should order the results by the street address, but firstly ordered by the street number part as numeric, and then by the street name.

 

The default query will return the results as follows:

 

Last comment 6 March 2018
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Let's say we have two serial classes, one as a property of another:

Class test.Serial Extends %SerialObject
{
Property Serial2 As test.Serial2;
}

Class test.Serial2 Extends %SerialObject
{
Property Property As %String;
}

And a persistent class, that has a property of test.Serial type:

Class test.Persistent Extends %Persistent
{

Property Datatype As %String;

Property Serial As test.Serial;

}

So it's a serial, inside a serial, inside a persistent object.

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Attached to this post is a PDF document outlining some of the key enhancements included with 2016.2. I will be giving a WebEx session that is open to all tomorrow at 11 AM EST. Once the WebEx is over I will be adding a link to the recording for those who cannot attend.

2016.2 Field Test Launch
Tuesday, February 2, 2016
11:00 am  |  Eastern Standard Time (New York, GMT-05:00)  |  30 mins
 
Meeting number:    747 673 229

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Our team is reworking an application to use REST services that use the same database as our current ZEN application. One of the new REST endpoints uses a query that ran very slowly when first implemented. After some analysis, we found that an index on one of the fields in the table greatly improved performance (a query that took 35 seconds was now taking a fraction of a second).

Last comment 23 August 2019
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Good afternoon everyone,

I hope you are well,

I am currently working on the below opportunity and if anyone here would like to hear more details please feel free to contact me on 01908 886 030 or teo.rusu@identifiglobal.com

Met with the client yesterday, beautiful office in Waterloo London, latest tech available with many benefits including working from home 2 days/w as well!

Intersystems Caché Senior Software Engineer

London

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This is a translation of the following article. Thanks [@Evgeny Shvarov] for the help in translation.

Someone posted a question on DC asking whether it was possible to determine access rights for a particular table row always at runtime, and if it was, how could one do that?
Answer: it is possible and it’s not hard at all.

Last comment 14 June 2017
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Caché Monitor is a database\sql tool primarily for InterSystems Caché but can also connect to MS SQL Server, MS Access and more databases. Within Caché Monitors Server Navigator you see all available Namespaces on your Caché Servers. No need to know the name of the Namespace, no need to configure many many JDBC Connections by hand. Just click on the namespace and see all objects like tables, views, classes and more...

Last comment 18 February 2016
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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)

Last comment 3 February 2016
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hi,

i have two where-clauses:

a)  ... WHERE company=1 and product=7

b)  ... WHERE product=7 and company=1 

with other words the position of the where fields are swapped.

now the question is:

bring the where clauses a) and b) the same performance(queryplan) or do i have to write it in a special order???

in my point of view, there is a  parser/optimizer who cares about this, so i don't have to care about. 

Last answer 6 September 2019
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