Link to an Oracle Database

Table 1 lists the parameters for a link to an Oracle database.

Do not change the password or user when the job is running. If you do so, the password will not take effect immediately and the job will fail.

**Table 1** Oracle database link parameters
Parameter	Description	Example Value
Name	Link name, which should be defined based on the data source type, so it is easier to remember what the link is for	oracle_link
Database Server	IP address or domain name of the database to connect	192.168.0.1
Port	Port of the database to connect	Default port: 1521
Connection Type	Oracle database connection type. The following options are available: Service Name: Use SERVICE_NAME to connect to the Oracle database. SID: Use SID to connect to the Oracle database.	SID
Instance Name	Oracle instance ID, which is used to differentiate databases by instances. This parameter is available only when Connection Type is set to SID.	dbname
Database Name	Name of the database to connect This parameter is available only when Connection Type is set to Service Name.	dbname
Username	Username used for accessing the database This account must have the permissions required to read and write data tables and metadata.	cdm
Password	Password of the username	-
Use Agent	Whether to extract data from the data source through an agent	Yes
Agent	Click Select and select the agent created in Managing Agents.	-
Oracle Version	Oracle database version. This parameter is available only for Oracle links. If java.sql.SQLException: Protocol violation is displayed, select another version.	Later than 12.1
Fetch Size	(Optional) Displayed when you click Show Advanced Attributes. Number of rows obtained by each request. Set this parameter based on the data source and the job's data size. If the value is either too large or too small, the job may run for a long time. A migration from the Oracle to DWS database may time out due to a long data write duration in the DWS database. In this case, reduce the value of Fetch Size for the Oracle database.	1000
Link Attributes	(Optional) Click Add to add the JDBC connector attributes of multiple specified data sources. For details, see the JDBC connector document of the corresponding database. The following are some examples: oracle.net.CONNECT_TIMEOUT=60000 and oracle.jdbc.ReadTimeout=300000: When a large amount of data needs to be migrated or the entire table is retrieved using query statements, the migration fails due to connection timeout. In this case, you can customize the connection timeout interval (ms) and read timeout interval (ms) to prevent failures caused by timeout.	sslmode=require
Reference Sign	(Optional) Delimiter between the names of the referenced tables or columns. For details, see the product documentation of the corresponding database.	"
Driver Version	Different types of relational databases adapt to different drivers. For details, see How Do I Obtain a Driver?	-