When a server process terminates, Adaptive Server can reuse its Process ID for a new process. Therefore, the Process ID data item is not guaranteed to uniquely identify a process. The Kernel Process ID data item, however, uniquely identifies a process.
To create a non-raw playback view that shows per-process data, the recording session view and the playback view must include both the Process ID and Kernel Process ID data items. If playback is raw, using only Process ID is allowed.
Views that include Process ID return rows as follows:
Recording session views and raw playback views.
These views return a row only for process IDs that exist at the end of a sample interval. If a server process terminates in the middle of a sample interval, a row is not returned for its process ID.
Playback views when the session’s summarization_level parameter is actual, entire, or user-defined intervals.
These views return rows for all server processes included in any of the input samples. However, since process IDs are not guaranteed to be unique, the Kernel Process ID data item must also be included to ensure uniqueness of the key. Otherwise, the view could erroneously summarize two different processes.