From 11g, OCI signal handling seem to have changed with introduction of ADR/FD infrastructure.
The DIAG_SIGHANDLER_ENABLED parameter is mentioned in OCI Programmer's guides, e.g. http://download.oracle.com/docs/cd/E11882_01/appdev.112/e10646/oci10new.htm#LNOCI16760 but not documented in the Net Services Reference.
http://download.oracle.com/docs/cd/E11882_01/network.112/e10835/sqlnet.htm#NETRF397 (even mentioned in the See Also section of OCI guide).
Edited by: orafad on May 4, 2011 11:47 AM
I asked the writer for that manual, who asked the development manager, who provided this answer:
"This parameter is applicable only to OCI clients. It does not apply generically to Net, hence not needed in Net manuals."