I began working with a legacy database for which there are no migrations.
After I setup my Rails app and verified the database connection in Rails console I began writing my first integration test. When I ran rspec it failed with a long exception whining about there being no SCHEMA_MIGRATIONS table.
ActiveRecord::StatementInvalid: ActiveRecord::JDBCError: java.sql.SQLSyntaxErrorException: ORA-00942: table or view does not exist
: SELECT "SCHEMA_MIGRATIONS".* FROM "SCHEMA_MIGRATIONS"
After a little grepping about I discovered the source of the problem in the default spec_helper.rb that rspec generated for me.
I deleted the following line and the spec ran as expected.
ActiveRecord::Migration.check_pending! if defined?(ActiveRecord::Migration)