External procedure - configuration problem

Question

Hi, I am trying to learn to use external procedures with PL/SQL but I have some problems with proper configuration.
I have created a *.dll library with class WriteStr containing one static method writeStr, which is supposed to write some text to file. Then, I've modified the (formerly default) listener.ora and tnsnames.ora files in the following way:
#listener.ora
SID_LIST_LISTENER =
(SID_LIST =
(SID_DESC =
(SID_NAME = orcl)
(ORACLE_HOME = C:\Program-Files\Oracle11g\product\11.2.0\dbhome_1)
LISTENER =
(DESCRIPTION_LIST =
(DESCRIPTION =
(ADDRESS_LIST =
(ADDRESS = (PROTOCOL = TCP)(HOST = localhost)(PORT = 1521))
SID_LIST_CALLOUT_LISTENER =
(SID_LIST =
(SID_DESC =
(SID_NAME = CLRExtProc)
(ORACLE_HOME = C:\Program-Files\Oracle11g\product\11.2.0\dbhome_1)
(PROGRAM = extproc)
(ENVS = "EXTPROC_DLLS=ONLY:C:\Program-Files\Oracle11g\product\11.2.0\dbhome_1\customlib\writestr.dll,C:\Program-Files\Oracle11g\product\11.2.0\dbhome_1\bin\oraclr11.dll,LD_LIBRARY_PATH=C:\Program-Files\Oracle11g\product\11.2.0\dbhome_1\lib")
CALLOUT_LISTENER =
(DESCRIPTION_LIST =
(DESCRIPTION =
(ADDRESS = (PROTOCOL = IPC)(KEY = extproc))
#tnsnames.ora
LISTENER_ORCL =
(DESCRIPTION =
(ADDRESS =
(PROTOCOL = TCP)
(HOST = localhost)
(PORT = 1521)
(CONNECT_DATA =
(SERVER = DEDICATED)
(SERVICE_NAME = ORCL)
ORACLR_CONNECTION_DATA =
(DESCRIPTION =
(ADDRESS_LIST =
(ADDRESS =
          (PROTOCOL = IPC)
          (KEY = extproc)
(CONNECT_DATA =
(SID = CLRExtProc)
(PRESENTATION = RO)
I've double-checked that the path specified in EXTPROC_DLLS does contain the *.dll file (don't be misled by "Program-Files", it's just a junction), and that both listeners are running. Creating the library and procedure wrapper:
CREATE OR REPLACE LIBRARY library_write_string AS
'C:\Program-Files\Oracle11g\product\11.2.0\dbhome_1\customlib\writestr.dll'
CREATE OR REPLACE PROCEDURE write_string
(path VARCHAR2, message VARCHAR2) AS
EXTERNAL LIBRARY library_write_string
NAME "WriteStr::writeStr"
PARAMETERS (path STRING, message STRING);
is succesful, however, upon trying to invoke write_string('C:\TEMP\file.txt','Hello, world!'), I get ORA-06520 (error loading external library).
What could possibly be the problem here? (that it's something with configuration is just my wild guess, if you see no problems above then I might as well have messed up something inside my *.dll file).

Answer 1

1. Didn't help.
2. Permissions set for all users on the *.dll file. Still nothing.
[Edit]
I tried setting EXTPROC_DLLS to ANY but nothing changed. In Oracle documentation, I found something about ENVS not being supported on Windows. Is it really the case? As far as I remember, the default listener.ora file contained an ENVS entry. If so, does any one know how to configure the listener properly?
Also, could somebody please comment on the following:
"Oracle Database 11g: PL/SQL Programing" says that external procedures require a separate listener. However, the default listener.ora file looks as follows:
SID_LIST_LISTENER =
(SID_LIST =
(SID_DESC =
(SID_NAME = CLRExtProc)
(ORACLE_HOME = C:\Program-Files\Oracle11g\product\11.2.0\dbhome_1)
(PROGRAM = extproc)
(ENVS = "EXTPROC_DLLS=ONLY:C:\Program-Files\Oracle11g\product\11.2.0\dbhome_1\bin\oraclr11.dll")
LISTENER =
(DESCRIPTION_LIST =
(DESCRIPTION =
(ADDRESS = (PROTOCOL = IPC)(KEY = EXTPROC1521))
(ADDRESS = (PROTOCOL = TCP)(HOST = localhost)(PORT = 1521))
ADR_BASE_LISTENER = C:\Program-Files\Oracle11g
My question is: will my computer explode when I append the path to my DLL to the EXPROC_DLLS variable? I know I could see for myself, but maybe there's a pretty good reason why I shouldn't use it like that. I'm a beginner so please don't laugh at me if what I'm saying sounds stupid.