A Walk in the Clouds

Please note:

1. I am neither promoting nor discouraging the use of any particular cloud service provider.

2. No Cats, Elephants, Monsters or Cloud providers were harmed in making this blog.

I recently encountered this issue while assisting a friend with her MSc project. She was irritated and complaining about “confusing” Postgres documentation.

➢She created a test Oracle database containing her project code.

➢She migrated Oracle to Postgres(RDS) using aws_sct and aws_dms.

➢After couple of days she took pg_dump of Postgres(RDS) and tried to restore on google cloud but it kept failing due to errors.

Here is the problem, Migrated PG RDS utilizes aws_oracle_ext extension pack and that won’t be available outside AWS. You can’t do straightforward dump and restore on different Cloud provider.

Source Oracle Code for reference :

This is mentioned in AWS’s documentation, and just like mutual funds, you should read the offer document carefully.

Special Mentions :

Prevention :
Ora2PG : Ora2pg use at first step could have prevented this problem. There are many other oracle to postgres migrators that avoid vendor lock.

Cure : After you made boo boo all over your application then there are not many options for cleanup.
Extensionmigrationassistant : Searched aws-oracle-ext on github and found this, they seem to help discover cloud native extensions used.

Did not find any more discussion on this topic probably (or fortunately) cause nobody uses databases this way in production or everyone accepts “once you go aws, you never go back”.