Odbc Oracle Review

If Excel (32-bit by default) cannot see your Oracle DSN, you installed a 64-bit driver. Install the 32-bit Instant Client instead.

This guide should give you everything needed to install, configure, and troubleshoot ODBC connections to Oracle Database across different platforms and applications. odbc oracle

| Problem | Likely Cause | Solution | |---------|--------------|----------| | ORA-12154: TNS could not resolve connect identifier | TNS name not found | Use Easy Connect string instead | | Oracle in Instant Client is not listed in ODBC admin | Driver not installed or 32/64-bit mismatch | Run the correct odbcad32.exe; reinstall driver | | ORA-12541: TNS no listener | Database listener not running or wrong port | Check lsnrctl status on Oracle server | | ORA-28009: connection as SYS should be as SYSDBA | Privilege issue | Use UID=sys;PWD=pass;Mode=SYSDBA | | IM004: Driver's SQLAllocHandle failed | Missing Oracle libraries | Check PATH/LD_LIBRARY_PATH | | Slow first query | Connection pool not used | Enable connection pooling in ODBC admin | If Excel (32-bit by default) cannot see your

If you have installed the full Oracle Client, the ODBC driver is likely installed automatically. If you are using the , follow these steps: | Problem | Likely Cause | Solution |

| Driver | Description | Best for | |--------|-------------|-----------| | | Older, included in older Oracle clients (10g, 11g). Deprecated but still used. | Legacy systems | | Oracle Instant Client ODBC Driver | Modern, lightweight, supports 12c, 18c, 19c, 21c, 23c. Recommended for all new deployments. | New applications, cloud, automation |