Retrieving the performance data is not without cost to the system, especially in terms of processor and memory requirements. In cases where your application does not need all the performance data, you can use the lpszValueName parameter of the RegQueryValueEx function to indicate the amount of information to retrieve. The following table lists the values you can specify for lpszValueName. Note that the value strings are case-sensitive, and if a string includes more than one word, your words must be separated by a space.
| Value | Description |
|---|---|
| Global | The function returns all data for counters on the local computer, except those included in the Costly category. |
| nnn xx yyy | Each of these is a Unicode string representing the decimal value for an object name index. The function only returns data about the specified object types on the local computer. For example, if your program were to use "2 4", the System and Memory objects would be retrieved. Note that more object types can be returned than are requested. This occurs when the requested object type depends on another object type. For example, processes are needed to identify threads, so information for the Process object is also returned when you request information for the Thread object. |
| Foreign ssss | The string ssss is the name of a foreign computer, such as a Novell NetWare server or a UNIX system. If your system is capable of collecting data from a foreign computer, the function returns all data for counters on the foreign computer. Try this approach if the RegConnectRegistry function fails to connect to a foreign computer. |
| Foreign ssss nnn xx yyy | This format combines Foreign ssss and nnn xx yyy. |
| Costly | The function returns data for object types whose data is expensive to collect in terms of processor time or memory usage. Start a worker thread if your application needs to respond to the user during this lengthy data collection. |