As I understand from this question my Sybase ASE database connection has its own SPID. My question is: are complex queries with nested subselects executed by that single SPID? Or does Sybase spawn other SPID's to execute complex queries?
If parallel processing is enabled, it is possible for spids to spawn other processes. This could occur in large complex queries if the optimizer chooses parallel execution, reorgs and other similar database actions.
If this occurs, then the newly spawned spid will have the parent spid in the fid (Family ID) column of master..sysprocesses, or in the out put of sp_who
More information on Parallel Queries can be found in the documentation.