Trouble using ODBC on Linux

Question

Hi there.
I'm fairly new to ODBC, so I apologize in advance if I am missing
some cirtical piece of information in my question.
I am trying to setup ODBC so that I can connect to my Oracle
database from RODBC (a package within the R statistical package),
where R is running on my Linux box where I installed the instant
client.
I have installed the 10.2.0.3 version of the instant client
(basic, odbc, and sqlplus pieces) on my Linux machine.
I have set LD_LIBRARY_PATH to include the new lib directory
/usr/lib/oracle/10.2.0.3/client/lib
which contains the libsqora.so.10.1 file.
uname -a yields the following:
Linux stacw34 2.6.9-78.0.0.0.1.ELsmp #1 SMP Fri Jul 25 14:41:56 EDT 2008 i686 i686 i386 GNU/Linux
I have set TNS_ADMIN to point to a directory with a tnsnames.ora
file that contains the following entry:
nickel =
(DESCRIPTION=
(ADDRESS=
(PROTOCOL=tcp)
(HOST=<my_machine>)
(PORT=1521)
(CONNECT_DATA=
(SERVICE_NAME=nickel.regress.rdbms.dev.us.oracle.com)
I have verified that the tnsnames entry is working correctly
by connecting to the database using the instant client sqlplus
executable.
At this point, I am trying to connect to the database using the
ODBC piece through RODBC. I have found that the errors I get from R
seem to be the same as those from isql, so I am trying to use
isql to find the root of the problem. Is there a better tool
to validate that ODBC is working on linux?
Anyway, I installed the odbc piece from the instant client, but
I had to do some editing by hand due to the way the machine
is configured. My /etc/odbcinst.ini file contains:
[PostgreSQL]
Description          = ODBC for PostgreSQL
Driver          = /usr/lib/libodbcpsql.so
Driver64          =
Setup          = /usr/lib/libodbcpsqlS.so
Setup64          =
UsageCount          =
CPTimeout          =
CPReuse          =
FileUsage          = 1
[Oracle 10g ODBC driver]
Description = Oracle ODBC driver for Oracle 10g
Driver = /usr/lib/oracle/10.2.0.3/client/lib/libsqora.so.10.1
Setup =
FileUsage =
CPTimeout =
CPReuse =
And my ~/.odbc.ini file contains:
[nickel]
Application Attributes = T
Attributes = W
BatchAutocommitMode = IfAllSuccessful
BindAsFLOAT = F
CloseCursor = F
DisableDPM = F
DisableMTS = T
Driver = Oracle 10g ODBC driver
DSN = nickel
EXECSchemaOpt =
EXECSyntax = T
Failover = T
FailoverDelay = 10
FailoverRetryCount = 10
FetchBufferSize = 64000
ForceWCHAR = F
Lobs = T
Longs = T
MetadataIdDefault = F
QueryTimeout = T
ResultSets = T
ServerName =
SQLGetData extensions = F
Translation DLL =
Translation Option = 0
DisableRULEHint = T
UserID =
When I run isql as follows:
isql -v nickel
I get the following error:
ORA-12162: TNS:net service name is incorrectly specified
It seems to be that this error occurs because I don't have
ORACLE_SID set. If I set ORACLE_SID to nickel, and then
run the same command, now I get:
ORA-12545: Connect failed because target host or object does not exist
The sqlnet.log file contains the following:
Fatal NI connect error 12545, connecting to:
(DESCRIPTION=(ADDRESS=(PROTOCOL=beq)(PROGRAM=/usr/lib/oracle/10.2.0.3/client/lib/bin/oracle)(ARGV0=oraclenickel)(ARGS='(DESCRIPTION=(LOCAL=YES)(ADDRESS=(PROTOCOL=beq)))')(DETACH=NO))(CONNECT_DATA=(CID=(PROGRAM=isql@<myhost>)(HOST=<myhost>)(USER=<myuser>))))
VERSION INFORMATION:
     TNS for Linux: Version 10.2.0.3.0 - Production
     Oracle Bequeath NT Protocol Adapter for Linux: Version 10.2.0.3.0 - Production
     TCP/IP NT Protocol Adapter for Linux: Version 10.2.0.3.0 - Production
Time: 20-MAR-2009 14:02:02
Tracing not turned on.
Tns error struct:
ns main err code: 12545
TNS-12545: Message 12545 not found; No message file for product=network, facility=TNS
ns secondary err code: 12560
nt main err code: 515
TNS-00515: Message 515 not found; No message file for product=network, facility=TNS
nt secondary err code: 2
nt OS err code: 0
I can't figure out what is wrong with my odbc setup which would lead
isql (and probably RODBC) to use this connect string (beq protocol, etc.).
I am guessing that is where the problem stems from.
Can you help me figure out how to find out what I am doing wrong
when configuring the odbc setup?
Thanks,
Ari
Edited by: amozes on Mar 20, 2009 11:06 AM

Answer 1

That's easily explained.
As you find documented in
http://download.oracle.com/docs/cd/B19306_01/install.102/b15699/post_inst_task.htm#sthref398
you have to set 'ServerName' in odbc.ini to your TNS alias, in your case:
ServerName = nickel
Since you did not give a ServerName, Oracle assumed that you want to connect to a local database.
As you rightly assume, the ORA-12162 indicates that ORACLE_SID is not set, which is needed for a local connection.
If you set ORACLE_SID, Oracle will try to establish a local connection by executing a server process $ORACLE_HOME/bin/oracle.
Since this executable cannot be found, you get the ORA-12545.
Yours,
Laurenz Albe
PS: Your solution is better, as it does not require a tnsnames.ora file.