Describe about product life cycle. For example, Microsoft, Apple, Oracle, etc.

Oracle Zero Downtime Migration (ZDM: Oracle DB Free Cloud Migration)

One of the questions when I create Oracle's cloud account, "I wonder how I move my oracle databases to the cloud."  

  • DataPump Export / Import (expdp / impdp)
    Also available in Standard edition
  • Data Guard
    Only available in Enterprise Edition
  • GoldenGate
    It needs additional paid license (GoldenGate)

You can choose many method if you have the money, but you need much money...

Now we can use Oracle GoldenGate equivalent tools free of charge

Its name is also called Oracle Zero Downtime Migration (ZDM)


What is Oracle Zero Downtime Migration

It is a tool that can complete the migration by taking only eight steps


(source :  

  • User Downloads and Configures ZDM

Download ZDM and configure it. ZDM runs on Oracle Linux 7 or above, and can be configured in the same server where the source database runs or a separate server.

Download ZDM and run it on Oracle Linux7 or above. (You can live with the DB server, or you can use another server.)

  • ZDM Starts Database Migration

Fill in the ZDM template file and start migration via the ZDMCLI command line. ZDM will connect to source and target with the provided SSH keys.

ZDM also has a template file and a "ZDMCLI" command line interface. It is necessary to be able to perform SSH communication to both the source and destination (it seems to be a point when migrating to the cloud, something like a VPN is essential)



  • ZDM Connects to Object Store

ZDM proceeds to connect the source database to the Oracle Object Store in the Cloud.

Object storage (Https connection) is required as a data storage used during migration. An area for storing things like GoldenGate Trail files, needed in the cloud. It looks like you can just use the one from Oracle Cloud.



  • ZDM Transfers Database Files

ZDM transfers all Database files, including a full backup and incremental archives.

 ZDM will transfer DB files and logs (Archive). Since it is described as Full Backup, after RMAN full backup transfer, an image that promotes differential transfer and differential application or GoldenGate-like log transfer and SQL application



  • ZDM Instantiates a Standby Database

ZDM instantiates a Standby database by leveraging the transferred files from source to the Object Store in the Oracle Cloud.

ZDM operation requires a standby database (similar to Data Guard, GoldenGate, etc.). It is similar to GoldenGate in terms of data transfer via Object Store on Oracle Cloud (unlike Data Guard which transfers redo raw)



  • ZDM Synchronized Primary to Standby

ZDM establishes SQLnet connectivity between source and target and then proceeds to synchronize the primary database on-premises and the standby database on the Oracle Cloud

After ZDM apparently establishes a SQLnet connection between the source and remotes, it move datas from the on-premise primary DB initiates to the remote cloud side DB. It seems that the ZDM server relays the session, or is a TCP session established between the primary and standby databases?



  • ZDM Switched Over Role Swap

ZDM then performs and controlled switchover and role swaps the databases. Now, the Oracle Database on-premises is a standby database and the Oracle Database on the Oracle Cloud is the primary.

ZDM seems to be able to switch roles. The role that can be changed to standby is the same as Data Guard and GoldenGate. 



  • User Finalized at Will

Finally, the user has control to finalize at will. ZDM will maintain SQLnet connectivity between source and target in order to guarantee synchronization between active (Oracle Database on the Oracle Cloud) and standby (Oracle Database on-premises) until instructed to finish by the user.

Finally, you can freely switch between the primary and standby modes (at any timing). 



Is ZDM free or need license fee?

ZDM is free. 

However, ZDM tool itself is free, and it goes without saying that a paid license and paid support for Oracle Database and Oracle Cloud are necessary.  
Over time, a lot of know-how will be shared, and cloud vendors are very active in sharing information in the community these days.  
Even though Oracle is a late-comer cloud vendor, there will be seminars to receive the know-how free of charge to migrate to cloud and to study sessions using migration tools to revitalize this community.  

Or does it exist as a tool, but will it be used only in the United States, and in Japan, the old Sier GoldenGate, RMAN, and Datapump will be used in a performance-oriented manner again? Partner companies that use Oracle must not have the same smell of legacy IT. It is a big difference from AWS. Oracle will need to establish a new partner in the cloud era.

Whether a downtime is required or not when migrate to Cloud

It seems you need to check it after actually touching it. It may be possible to perform non-stop from the AP server (= Oracle client), but it is unknown whether the business can be performed without stopping, and it is not known whether the migration including the AP server can be performed without stopping.

I will keep you updated if you know the details.

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