Migration assessment

Migration assessment

 

1rst Method

We use 3 servers :

·         Management server : which hosts ora2pg server, open flow between the oracle server and the management server. Open flow between PostgreSQL server and the management server.

·         The oracle server : which hosts the source database.

·         The postgresql server : which hosts the target database.

In this method, all the servers are virtual machines.

- The oracle server already exists.

- The management server must be created only for the migration purpose then it can be deleted.

- The postgresql server is a temporary virtual machine created only for the migration purpose then it can be deleted.

The method consists in the logical backup of the databases migrated from oracle to postgresql.

Then the backup is imported in the cloud databases.

Benefit of this method :

-          easy to implement

-          automation is possible

-          can be optimize with tuning os and parameters

Disadvantage :

-          Not the customer method ?

-          Need to create a virtual machine

 

2^nd method

We use 3 environments

·         Management server : which hosts ora2pg server, open flow between the oracle server and the management server.

·         The oracle server : which hosts the source database.

·         The postgresql in the cloud  : which hosts the target database.

The method consists in the extraction of the oracle data into SQL files.

Then the files are imported in the cloud databases.

Benefit of this method :

-          The final data are directly recoverable

-          No need to create virtual machines

Disadvantage :

-          Not easy to implement;

-          Can become very long for large databases;

-          Cannot be optimized;

 

 3^rd method

The method consists in the automation of the migration process from an oracle database into the postgresql cloud.

 Benefit of this method :

-          The final data are directly recoverable

-          No need to create virtual machines

-          The migration is fast and can be run by ora2pg for DDL and DML.

Disadvantage :

-          Not easy to implement;

-          Need the flow opened between the ora2pg server and the postgresql cloud database