What is the data source of oracle?

In Oracle, the data source is an abstraction of data connection, including information such as database location and database type; the data source provides the function of reading and writing Oracle bidirectional channels, which can be easily accessed through the wizard mode and script mode to configure data synchronization tasks.

The operating environment of this tutorial: Windows 10 system, Oracle 11g version, Dell G3 computer.

What is the data source of oracle?

Data source. The data source contains information such as database location and database type, and is actually an abstraction of data connection.

Oracle data source provides you with the function of reading and writing Oracle bidirectional channels, so that you can subsequently configure data synchronization tasks through wizard mode and script mode. This article introduces you to the network environment and account permissions that need to be prepared before configuring the data source, and how to add an Oracle data source in DataWorks.

Prerequisites

Before configuring the data source, please ensure that the following planning and preparations have been completed.

• Prepare the data source: The source data source Oracle has been purchased.

• Resource planning and preparation: An exclusive data integration resource group has been purchased and resource configuration has been completed. For details, see Resource Planning and Configuration.

• Network environment assessment and planning: Before adding a data source, you need to open the network between the data source and the exclusive data integration resource group according to the business situation, and conduct switches, whiteboards, etc. Access configuration in network environments such as lists.

If the data source and the exclusive data integration resource group are in the same VPC network in the same region, the network between the data source and the resource group is naturally connected.

If the data source and the exclusive data integration resource group are in different network environments, you need to open the network between the data source and the resource group through a VPN gateway or other methods.

• Prepare the account and authorize it:

You need to plan an account that can access the data source for accessing the data source during the subsequent data integration process. And perform synchronization operations of data extraction and writing.

• Enable supplementary logs:

When the source data source is Oracle, you need to enable database-level archive logs, Redo logs and supplementary logs.

Archived logs: Oracle saves all redo history records through archive logs, which are used to completely restore the database in the event of a database failure.

Redo log: Oracle uses the Redo log to ensure that database transactions can be re-executed, so that the data can be recovered after a failure (such as a power outage), so you need to enable and switch the Redo log for the database.

Supplementary log: The supplementary log is a supplement to the information in the Redo log. In Oracle, the Redo log is used to record the values ​​of modified fields, and the supplementary log is supplementary information to the change records in the Redo log, which ensures that Oracle's Redo log contains complete information describing all data changes for data recovery. , data synchronization and other operations, the complete statement and related changes can be traced back. Some functions of the Oracle database require supplemental logging to be enabled to work properly or better, so you need to enable supplemental logging for the database.

For example, if supplementary logging is not enabled, after executing the UPDATE command, only the field values ​​changed by the UPDATE command will be recorded in the Redo log. After supplementary logging is enabled, the modified fields and modifications will be recorded in the Redo log. The previous value, the modified value, and the conditional value of the modified target field. When a database failure occurs (such as a power outage), you can recover the data based on this modification information.

When using data integration, it is recommended to enable the primary key column or unique index column supplementary log.

After turning on the supplementary log of the primary key column, if there are any updates to the database, all columns that make up the primary key will be recorded in the log.

After turning on the supplementary log of unique index columns, if any column that makes up the unique key or bitmap index is modified, the columns that make up the unique key or bitmap index will be recorded in the log.

Oracle only supports opening supplementary logs in the main database or standby database.

• Check the character encoding format of the database:

You need to ensure that Oracle cannot contain character encoding formats that are not supported by data integration to prevent data synchronization fail. When the current data integration synchronizes data, only UTF8, AL32UTF8, AL16UTF16 and ZHS16GBK encoding formats are supported.

• Check the data type of the database table:

You need to ensure that Oracle cannot contain data types that are not supported by data integration to prevent data synchronization failure . When current data integration performs real-time synchronization, LONG, BFILE, LONG RAW and NCLOB data types are not supported.

Recommended tutorial: "Oracle Video Tutorial"

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