Critical severityconnectivity
Oracle Database Error:
ORA-12545
What does this error mean?
TNS could not connect because the target host name could not be resolved (DNS failure) or the host refused the connection.
Common causes
- 1Host name in the connection string cannot be resolved by DNS
- 2Oracle host was decommissioned or renamed but the connection string was not updated
- 3Incorrect host name in tnsnames.ora or the JDBC URL
- 4DNS is not configured on the pipeline server for the Oracle host's domain
How to fix it
- 1Step 1: Test DNS resolution from the pipeline server: `nslookup <oracle_host>` or `host <oracle_host>`.
- 2Step 2: Update the connection string to use an IP address if DNS is not available.
- 3Step 3: Add a hosts file entry if DNS cannot be configured: `/etc/hosts` or `C:\Windows\System32\drivers\etc\hosts`.
- 4Step 4: Verify the host name is correct and matches the Oracle server's fully qualified domain name.
- 5Step 5: Update tnsnames.ora or the ADF linked service with the correct host name or IP.
Example log output
ORA-12545: Connect failed because target host or object does not exist