Thanks Connor for the insight.
We've run some checks and i'm in the position to share the results:
(1) `expdp` is not working with UNC shares, nor with driver letters that are not local drives (network shares mapped as local drives).
Connected to: Oracle Database 19c Enterprise Edition Release 184.108.40.206.0 - Production
Starting "SYS"."SYS_EXPORT_FULL_08": "SYS/********@DB_NAME AS SYSDBA" PARFILE=E:\temp\export_full.par
ORA-39155: error expanding dump file name "\\SERVERNAME\EXPORT\FILE.DMP"
ORA-48128: opening of a symbolic link is disallowed
(2) `rman` is working with UNC shares
(3) We could follow the advice and create a domain account for (a) running Oracle db services (making it part of the local ora_dba group should be enough, isn't it ?) and (b) write permission on UNC shares, but we still need to figure out a solution for DB servers outside the domain.
(4) Oracle 19 post-upgrade recommended actions are conflicting with MOS 739772.1 in terms of using UNC shares; so, in the end, which side of the coin is valid (use/avoid UNC shares) ? Probably the answer here is `it depends` on the program...
October 29, 2020 - 2:51 am UTC
With (1) and (4) I think thats worth taking up with Support for clarification.
The "ORA-48128: opening of a symbolic link is disallowed" is a security fix, because you could as a non-priv'd user, create a symlink to (say) an Oracle datafile and then run a dump or utl_file etc etc and .... splat.
I guess the same *could* be done with a UNC name.