Why is the schema/structure dump so slow?

I'm using Rails 6 with activerecord-oracle_enhanced-adapter adapter for Oracle 11 XE database. At the beginning of the project I was working with Postgres, but due to customer requirements I had to migrate to Oracle. My question is very similar to https://stackoverflow.com/questions/592444/rails-rake-dbmigrate-very-slow-on-oracle , but it's from 11 years ago, i'm using the updated version of the adapter. I know that after all migrations are applied to database then rake db:migrate calls db:schema:dump task to generate schema.rb file from current database schema. I only have one schema, with many tables (around 90) The answer for the previous question was something like > One way how to debug this issue would be if you would put some debug > messages in oracle_enhanced_adapter.rb file so that you could identify > which method calls are taking so long time. == 20200820164111 RemoveSemesterFromProject: migrated (0.1347s) =============== real 13m26,038s user 0m5,494s sys 0m0,401s All migrations finished in an reasonable time, so I think the error occurs in the following action "db: schema: dump" but i don't have oracle_enchaced_adapter.rb neither oracle_enhanced_adapter.rb, so i don't know where to look at. What can i do for improve this behaviour? Time that takes when i run db:schema:dump

real	9m44,074s
user	0m3,701s
sys	0m0,327s

and this is the time that takes when i run db:structure:dump

real	21m40,073s
user	0m5,046s
sys	0m0,413s