#Tips & Tricks

Here is a snippet that I learned yesterday

You can define an index on a collection property but when I tried to use it, I failed. I was using

     Select ….. where …. :xx %INLIST collproperty

But this will not use an index, but the equivalent syntax

     SELECT .. WHERE ... FOR SOME %ELEMENT(collproperty) (%VALUE=:xx)

will use the index

Check out

http://docs.intersystems.com/latest/csp/docbook/DocBook.UI.Page.cls?KEY=...

the useful content is in the replies
showing the use of $SYSTEM.OBJ.ValidateIndices()

Sometimes you can face the situation when you did update the web app on Caché server but you cannot get the newest version of the app in a browser.

Here are couple recipes which help me to solve it. From simplest to more sophisticated and not obvious.

1. Refresh page in a browser

In Chrome it is Ctrl+R or 'Refresh' button. Obvious, but helpful.

2. Hard reset in a browser

If you are in Chrome, open Developer tools

If you have an app that uses some Caché client Windows components that are not included into CacheODBC distribution (e.g. CacheActiveX.dll), you need to proceed Caché client installation on end user's client computers and/or MS Terminal Servers. Being a part of Caché client's installation, Caché Cube is installed along with other components and is autostarted with every user's session. So, it becomes visible to every user.

To make it completely invisible, you can just move CACHE.lnk file from

Introduction

Twilio is a great tool for programmatically initiating and managing phone calls. In this example we'll go over basic account setup, create a Cache Class to manage our interaction with the Twilio API, and initiate a phone call from the Cache Terminal.

The full Class used in this example is available on GitHub as well.

I wanted to share a little tidbit which is in the Studio documentation (http://docs.intersystems.com/cache20152/csp/docbook/DocBook.UI.Page.cls?...) but many people who have been using the InterSystems Studio for a long time missed the addition of this *very* useful feature, and every time I mention this to an audience I see at least one face light up because of how excited they are to learn about it!

Within Studio, the Output pane (View -> Output) is actually misnamed. It is actually an Input/Output window which can be used to run Caché ObjectScript commands!

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.

When working at a terminal prompt the %SS routine lets me see what's running on the instance:

USER>d ^%SS

But sometimes I'm only interested in knowing what's running in my namespace. In which case, here's what I use:

USER>d THIS^%SS

Hi All

I'm looking for some field experiences, lessons learned, or actual deployed solutions to the problem of replicating non-CACHE.DAT data in a mirrored Cache environment.

Environment:

• Operating System is IBM AIX
• Hardware is IBM Power w/ virtualised storage
• Cache 2017.1
• 2x Production mirror members
• 1x DR mirror member

If your application is raising <PROTECT> errors and you're finding it hard to work out why, here's a way to get additional information.

First, if auditing is not already enabled, turn it on:

Then use "Configure System Events" (highlighted above) and locate the event named %System/%Security/Protect. In the screenshot below I used the Filter field to do this (type "protect" - highlighted below - and press TAB):

It's almost time to get your customers upgraded to new versions - are you worried about showing off your SQL Performance after upgrades? If you want to upgrade without worrying, then I have just the program for you!!! Check out this video from Global Summit 2016 featuring yours truly explaining how to upgrade a system without worrying about pesky SQL queries showing on your waistline!

https://www.youtube.com/watch?v=GfFPYfIoR_g

Sometimes I observe people scrolling manually down to the bottom of the Console Log document when they want to see the most recent messages. So I want to draw attention to the handy link that does the job for you in a single click:

Inspired by the article "Declarative development in Caché" that's still trending on the dev com. The OP explored a functional style of iterating over a collection. A comment today suggested "Caché would need syntax support for anonymous functions".

With Macros you can kind of get anonymous like syntax using dot notation.

This is not production code, but it does work. First the macros...

In case you've never used the "About" link at the top of Management Portal, here's a screenshot of the kind of information it shows. I've highlighted the link and some of the information I find it handy to get from here.