Attribute and attribute group characteristics
Formula functions treat attributes as numeric, text or timestamp. Attributes also have other characteristics that further categorize them and inform your choice of formula function or query-based view..
- Numeric
Numeric attributes can
represent a percentage, seconds, bytes or some other unit of measurement. When entering a hexadecimal value in a cell, prefix the number with zero and the letter “x”, as in 0x123ab for hex value 123ab. In z/OS applications, for example, DASD volume serial numbers are hexadecimal.
- Text
Single quotation marks are
required around multiple-word text values. The timestamp and, usually,
enumerated attributes are treated as text attributes. - Words with apostrophes, such as that's or agent's,
cannot be used. Instead, consider using a wildcard or, if appropriate,
use
Return a subset of the
string or or 
Scan for string within a string and
specify the letters preceding the apostrophe. - You can use an * asterisk wildcard to begin or end the attribute
value in a
Value
of expression (Equal operator only), 
Check for Missing Items, Scan for string within a string, or Return a subset of the string function. - You can also use the ? question mark wildcard for a single character
at that position. When using the ? question mark wildcard with the Value of
expression function, append the text with an * asterisk. For example, enter Sa?e* to
find Safe and Sale.
- Timestamp
The Timestamp attribute is
treated like a text attribute formatted as mm/dd/yy hh:mm:ss. Some
timestamp attributes have different names, such as Start Date &
Time and Recording Time. Some timestamp functions enable you to add and subtract values from the second attribute by using the + and - symbols. The value can be one or two digits followed by D for Day, H for Hour, M for Minute, or S for Second.
- Enumerated
- Enumerated attributes have a predefined set of
values and the tabular editor supplies a
list to choose from. These values are usually treated as
text. Some enumerated values are actually numeric, with text representing some or all of the numbers, and you can type the numeric value instead of choosing a text equivalent from a list. For example, the WebSphere MQ attribute, Action to Take has values of n/a, delete, create, and discover. But you can also enter 5 or 6, which represent other actions. See the help topic of the attribute in question for a list of possible entries.
- Single-row or multiple-row
- Depending on the type of attribute group, data samplings return
either a single row of data or multiple rows. For example, the Windows
Memory attribute group returns one row of a data for a managed system,
whereas the Windows Process attribute group returns multiple rows,
one for each process running.
A single-row attribute group will return multiple rows if it has been configured for historical data collection.
Attributes from different attribute groups can be combined in the same situation if they are from single-row attribute groups. Local Time and Universal Time are the exception—they can be combined with any group.
When you create a query for an attribute group that returns multiple rows, consider adding a formula as a pre-filter to limit the rows returned to those of interest, which also reduces network traffic overhead.
- Pure or sampled
- Attributes behave differently in situations depending on whether
they are able to be sampled at intervals. Attributes that cannot be
sampled are those that have no value until something happens, such
as those for the Windows OS File Change attribute group. These unsolicited
notifications are called pure events Examples of pure events
are an out-of-paper condition on a printer and an occurrence that
adds an entry to the Windows System Log.
Events from sampled situations are closed automatically when the situation is no longer true (goes back to false). Because of the nature of pure events, they are not closed automatically like sampled events but must be closed manually unless an Until clause is included in the situation definition.