Do you know which tables in Oracle are spatial and which are not?

If you do, you can set up one Oracle Spatial reader and one Oracle Non-Spatial reader, then add a writer to PostGIS and simply duplicate the input feature types as output feature types. When you create the writer there’s a Table Definition parameter allowing you to copy them from the readers. 

That’s where the fun starts though, if PostGIS enforces different rules on attribute and table names than Oracle that’ll be reflected in the output feature types. You also apparently want to rename tables anyway, so you are going to have to go through and sort that out. If it’s something basic like put all attribute names in lowercase there’s a BulkAttributeRenamer that you can use.

​@redgeographics 

thanks for your response.

I can manage to migrate table 1 by 1.
however, there are dozens (and then 2 databases with even more tables).

I'm stuck on that.

I saw a possible solution in post https://community.safe.com/data-7/lowercase-postgis-table-names-3910

I think the last response in this post is a solution. I tried this, but it doesn't work very well and I don't know what to enter for some transformers.

Can you explain why it does not work very well? We might be able to help you better if we know.

And I don’t want to discourage you, but migrating a large schema from one format to the other is going to take time and effort. 

-schema names in the new database are correct.

-Nr of records pro table in the new database are correct.

But the data and columns are not migrated.