Using Caché Multi-Dimensional Storage - InterSystems ...

Testing the Existence of a Global Node
KILL ^Data(100)
deletes contents of node 100 within the ^Data global. If there are descendant subnodes, such
as ^Data(100,1), ^Data(100,2), and ^Data(100,1,2,3), these are deleted as well.
The Caché ObjectScript ZKILL command deletes a specified global or global subscript node.
It does not delete descendant subnodes.
You cannot use the NEW command on global variables.
3.3 Testing the Existence of a Global Node
You can test if a specific global (or its descendants) contains data using the Caché ObjectScript
$DATA function.
$DATA returns a value indicating whether or not the specified global reference exists. The
possible return values are:
Status
Value
0
1
10
11
Meaning
The global variable is undefined.
The global variable exists and contains data, but has no descendants. Note
that the null string ("") qualifies as data.
The global variable has descendants (contains a downward pointer to a
subnode) but does not itself contain data. Any direct reference to such a
variable will result in an error. For example, if $DATA(^y)
returns 10, SET x=^y will produce an error.
The global variable both contains data and has descendants (contains a
downward pointer to a subnode).
3.4 Retrieving the Value of a Global Node
You can get the value stored within a specific global node by simply using the global reference
as an expression.
Using Caché Basic:
Using Caché Multi-Dimensional Storage 19