#Tips & Tricks

I was recently troubleshooting a problem on a Linux (RHEL) instance of 2016.1 at a site. For policy reasons their sysadmins wanted to update the Caché installation so it used network accounts for its cacheusr and iscagent users and groups instead of the locally-created ones that had been set up during original install of Caché.

To do this they ran various commands including chown

Afterwards non-root users couldn't obtain a terminal session using the csession command.

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:

/// Stores unique identifiers
Class Utils.Pool Extends %Persistent
{

Property Value As %String;

Index IDKEY On Value [ IdKey, PrimaryKey, Unique ];

Method %OnNew(Value As %String = "") As %Status [ Private, ServerOnly = 1 ]
{
    Set ..Value = Value
    Quit $$$OK
}

ClassMethod Add(Value As %String = "")
{
    Quit:..%ExistsId(Value)
    Set Obj = ..%New(Value)
    Do Obj.%Save()
}

Storage Default
{
<Data name="PoolDefaultData">
<Value name="1">
<Value>%%CLASSNAME</Value>
</Value>
</Data>
<DataLocation>^||Utils.PoolD</DataLocation>
<DefaultData>PoolDefaultData</DefaultData>
<IdLocation>^||Utils.PoolD</IdLocation>
<IndexLocation>^||Utils.PoolI</IndexLocation>
<StreamLocation>^||Utils.PoolS</StreamLocation>
<Type>%Library.CacheStorage</Type>
}
}

Hi, Community!

You know, that when we build hierarchies in DeepSee dimension all the members of lower level should be the part of one member of the higher level.

If not you'll get some empty results in MDX queries with this hierarchy.

With Time dimensions the obvious valid hierarchy is Year->Month->Day, cause every Month consists of one Year and every day consists of one month. 

But be aware of using Year->Month->Week->Day hierarchy. In this case, there are some weeks in the year (most of them), which consist of two months.

(Possibly?) little-known fact: It's possible to use $ListBuild on the left hand side of the equals sign in a set command to extract multiple list values at once:

For example:

See for reference: http://docs.intersystems.com/cache20152/csp/docbook/DocBook.UI.Page.cls…

This feature was news to me - I use $ListBuild lists a lot but hadn't come across it until today.

Here are a few tips that might be useful to people who are running applications in an environment that's configured to use InterSystems mirroring.

• If you configure an ECP connection to a Caché instance that is a mirror member databases then the ECP connection should also have mirroring enabled (tick the mirroring box when defining the connection). More details here. You may also need to increase the number of ECP connections each end accepts, to cater for the way both members of a mirror pair get involved in ECP negotiation.