diff --git a/lib/active_record/connection_adapters/oracle_enhanced/database_statements.rb b/lib/active_record/connection_adapters/oracle_enhanced/database_statements.rb
index 0bc96bf1b..22f2d2d0c 100644
--- a/lib/active_record/connection_adapters/oracle_enhanced/database_statements.rb
+++ b/lib/active_record/connection_adapters/oracle_enhanced/database_statements.rb
@@ -12,7 +12,7 @@ module DatabaseStatements
         def execute(sql, name = nil, async: false)
           sql = transform_query(sql)
 
-          log(sql, name, async: async) { @raw_connection.exec(sql) }
+          log(sql, name, async: async) { _connection.exec(sql) }
         end
 
         def exec_query(sql, name = "SQL", binds = [], prepare: false, async: false)
@@ -25,10 +25,10 @@ def exec_query(sql, name = "SQL", binds = [], prepare: false, async: false)
             cached = false
             with_retry do
               if without_prepared_statement?(binds)
-                cursor = @raw_connection.prepare(sql)
+                cursor = _connection.prepare(sql)
               else
                 unless @statements.key? sql
-                  @statements[sql] = @raw_connection.prepare(sql)
+                  @statements[sql] = _connection.prepare(sql)
                 end
 
                 cursor = @statements[sql]
@@ -101,10 +101,10 @@ def exec_insert(sql, name = nil, binds = [], pk = nil, sequence_name = nil)
             returning_id_col = returning_id_index = nil
             with_retry do
               if without_prepared_statement?(binds)
-                cursor = @raw_connection.prepare(sql)
+                cursor = _connection.prepare(sql)
               else
                 unless @statements.key?(sql)
-                  @statements[sql] = @raw_connection.prepare(sql)
+                  @statements[sql] = _connection.prepare(sql)
                 end
 
                 cursor = @statements[sql]
@@ -141,12 +141,12 @@ def exec_update(sql, name = nil, binds = [])
             with_retry do
               cached = false
               if without_prepared_statement?(binds)
-                cursor = @raw_connection.prepare(sql)
+                cursor = _connection.prepare(sql)
               else
                 if @statements.key?(sql)
                   cursor = @statements[sql]
                 else
-                  cursor = @statements[sql] = @raw_connection.prepare(sql)
+                  cursor = @statements[sql] = _connection.prepare(sql)
                 end
 
                 cursor.bind_params(type_casted_binds)
@@ -164,7 +164,7 @@ def exec_update(sql, name = nil, binds = [])
         alias :exec_delete :exec_update
 
         def begin_db_transaction # :nodoc:
-          @raw_connection.autocommit = false
+          _connection.autocommit = false
         end
 
         def transaction_isolation_levels
@@ -183,15 +183,15 @@ def begin_isolated_db_transaction(isolation)
         end
 
         def commit_db_transaction # :nodoc:
-          @raw_connection.commit
+          _connection.commit
         ensure
-          @raw_connection.autocommit = true
+          _connection.autocommit = true
         end
 
         def exec_rollback_db_transaction # :nodoc:
-          @raw_connection.rollback
+          _connection.rollback
         ensure
-          @raw_connection.autocommit = true
+          _connection.autocommit = true
         end
 
         def create_savepoint(name = current_savepoint_name) # :nodoc:
@@ -265,14 +265,14 @@ def write_lobs(table_name, klass, attributes, columns) # :nodoc:
                 raise ActiveRecord::RecordNotFound, "statement #{sql} returned no rows"
               end
               lob = lob_record[col.name]
-              @raw_connection.write_lob(lob, value.to_s, col.type == :binary)
+              _connection.write_lob(lob, value.to_s, col.type == :binary)
             end
           end
         end
 
         private
           def with_retry
-            @raw_connection.with_retry do
+            _connection.with_retry do
               yield
             rescue
               @statements.clear
diff --git a/lib/active_record/connection_adapters/oracle_enhanced/oci_quoting.rb b/lib/active_record/connection_adapters/oracle_enhanced/oci_quoting.rb
index 972fe2209..139994bf9 100644
--- a/lib/active_record/connection_adapters/oracle_enhanced/oci_quoting.rb
+++ b/lib/active_record/connection_adapters/oracle_enhanced/oci_quoting.rb
@@ -9,19 +9,19 @@ def type_cast(value)
           when ActiveModel::Type::Binary::Data
             lob_value = value == "" ? " " : value
             bind_type = OCI8::BLOB
-            ora_value = bind_type.new(@raw_connection.raw_oci_connection, lob_value)
+            ora_value = bind_type.new(_connection.raw_oci_connection, lob_value)
             ora_value.size = 0 if value == ""
             ora_value
           when Type::OracleEnhanced::Text::Data
             lob_value = value.to_s == "" ? " " : value.to_s
             bind_type = OCI8::CLOB
-            ora_value = bind_type.new(@raw_connection.raw_oci_connection, lob_value)
+            ora_value = bind_type.new(_connection.raw_oci_connection, lob_value)
             ora_value.size = 0 if value.to_s == ""
             ora_value
           when Type::OracleEnhanced::NationalCharacterText::Data
             lob_value = value.to_s == "" ? " " : value.to_s
             bind_type = OCI8::NCLOB
-            ora_value = bind_type.new(@raw_connection.raw_oci_connection, lob_value)
+            ora_value = bind_type.new(_connection.raw_oci_connection, lob_value)
             ora_value.size = 0 if value.to_s == ""
             ora_value
           else
diff --git a/lib/active_record/connection_adapters/oracle_enhanced/schema_statements.rb b/lib/active_record/connection_adapters/oracle_enhanced/schema_statements.rb
index 8ddf1d022..45333bd7f 100644
--- a/lib/active_record/connection_adapters/oracle_enhanced/schema_statements.rb
+++ b/lib/active_record/connection_adapters/oracle_enhanced/schema_statements.rb
@@ -53,7 +53,7 @@ def table_exists?(table_name)
         end
 
         def data_source_exists?(table_name)
-          (_owner, _table_name) = @raw_connection.describe(table_name)
+          (_owner, _table_name) = _connection.describe(table_name)
           true
         rescue
           false
@@ -87,7 +87,7 @@ def synonyms
         end
 
         def indexes(table_name) # :nodoc:
-          (_owner, table_name) = @raw_connection.describe(table_name)
+          (_owner, table_name) = _connection.describe(table_name)
           default_tablespace_name = default_tablespace
 
           result = select_all(<<~SQL.squish, "SCHEMA", [bind_string("table_name", table_name)])
@@ -368,7 +368,7 @@ def index_name(table_name, options) # :nodoc:
         #
         # Will always query database and not index cache.
         def index_name_exists?(table_name, index_name)
-          (_owner, table_name) = @raw_connection.describe(table_name)
+          (_owner, table_name) = _connection.describe(table_name)
           result = select_value(<<~SQL.squish, "SCHEMA", [bind_string("table_name", table_name), bind_string("index_name", index_name.to_s.upcase)])
             SELECT 1 FROM all_indexes i
             WHERE i.owner = SYS_CONTEXT('userenv', 'current_schema')
@@ -511,7 +511,7 @@ def change_column_comment(table_name, column_name, comment_or_changes)
 
         def table_comment(table_name) # :nodoc:
           # TODO
-          (_owner, table_name) = @raw_connection.describe(table_name)
+          (_owner, table_name) = _connection.describe(table_name)
           select_value(<<~SQL.squish, "SCHEMA", [bind_string("table_name", table_name)])
             SELECT comments FROM all_tab_comments
             WHERE owner = SYS_CONTEXT('userenv', 'current_schema')
@@ -527,7 +527,7 @@ def table_options(table_name) # :nodoc:
 
         def column_comment(table_name, column_name) # :nodoc:
           # TODO: it  does not exist in Abstract adapter
-          (_owner, table_name) = @raw_connection.describe(table_name)
+          (_owner, table_name) = _connection.describe(table_name)
           select_value(<<~SQL.squish, "SCHEMA", [bind_string("table_name", table_name), bind_string("column_name", column_name.upcase)])
             SELECT comments FROM all_col_comments
             WHERE owner = SYS_CONTEXT('userenv', 'current_schema')
@@ -555,7 +555,7 @@ def tablespace(table_name)
 
         # get table foreign keys for schema dump
         def foreign_keys(table_name) # :nodoc:
-          (_owner, desc_table_name) = @raw_connection.describe(table_name)
+          (_owner, desc_table_name) = _connection.describe(table_name)
 
           fk_info = select_all(<<~SQL.squish, "SCHEMA", [bind_string("desc_table_name", desc_table_name)])
             SELECT r.table_name to_table
diff --git a/lib/active_record/connection_adapters/oracle_enhanced_adapter.rb b/lib/active_record/connection_adapters/oracle_enhanced_adapter.rb
index eca568235..5c0cfbaac 100644
--- a/lib/active_record/connection_adapters/oracle_enhanced_adapter.rb
+++ b/lib/active_record/connection_adapters/oracle_enhanced_adapter.rb
@@ -432,12 +432,13 @@ def native_database_types # :nodoc:
 
       def auto_retry=(value) # :nodoc:
         @auto_retry = value
-        @raw_connection.auto_retry = value if @raw_connection
+        _connection.auto_retry = value if _connection
       end
 
       # return raw OCI8 or JDBC connection
       def raw_connection
-        @raw_connection.raw_connection
+        verify!
+        _connection.raw_connection
       end
 
       # Returns true if the connection is active.
@@ -446,13 +447,13 @@ def active? # :nodoc:
         # #active? method is also available, but that simply returns the
         # last known state, which isn't good enough if the connection has
         # gone stale since the last use.
-        @raw_connection.ping
+        _connection.ping
       rescue OracleEnhanced::ConnectionException
         false
       end
 
       def reconnect
-        @raw_connection.reset # tentative
+        _connection.reset # tentative
       rescue OracleEnhanced::ConnectionException
         connect
       end
@@ -460,7 +461,7 @@ def reconnect
       # Reconnects to the database.
       def reconnect! # :nodoc:
         super
-        @raw_connection.reset!
+        _connection.reset!
       rescue OracleEnhanced::ConnectionException => e
         @logger.warn "#{adapter_name} automatic reconnection failed: #{e.message}" if @logger
       end
@@ -478,12 +479,12 @@ def reset!
       # Disconnects from the database.
       def disconnect! # :nodoc:
         super
-        @raw_connection.logoff rescue nil
+        _connection.logoff rescue nil
       end
 
       def discard!
         super
-        @raw_connection = nil
+        _connection = nil
       end
 
       # use in set_sequence_name to avoid fetching primary key value from sequence
@@ -508,7 +509,7 @@ def prefetch_primary_key?(table_name = nil)
         table_name = table_name.to_s
         do_not_prefetch = @do_not_prefetch_primary_key[table_name]
         if do_not_prefetch.nil?
-          owner, desc_table_name = @raw_connection.describe(table_name)
+          owner, desc_table_name = _connection.describe(table_name)
           @do_not_prefetch_primary_key[table_name] = do_not_prefetch = !has_primary_key?(table_name, owner, desc_table_name)
         end
         !do_not_prefetch
@@ -577,7 +578,7 @@ def default_tablespace
       end
 
       def column_definitions(table_name)
-        (owner, desc_table_name) = @raw_connection.describe(table_name)
+        (owner, desc_table_name) = _connection.describe(table_name)
 
         select_all(<<~SQL.squish, "SCHEMA", [bind_string("owner", owner), bind_string("table_name", desc_table_name)])
           SELECT cols.column_name AS name, cols.data_type AS sql_type,
@@ -609,7 +610,7 @@ def clear_table_columns_cache(table_name)
       # Find a table's primary key and sequence.
       # *Note*: Only primary key is implemented - sequence will be nil.
       def pk_and_sequence_for(table_name, owner = nil, desc_table_name = nil) # :nodoc:
-        (owner, desc_table_name) = @raw_connection.describe(table_name)
+        (owner, desc_table_name) = _connection.describe(table_name)
 
         seqs = select_values_forcing_binds(<<~SQL.squish, "SCHEMA", [bind_string("owner", owner), bind_string("sequence_name", default_sequence_name(desc_table_name))])
           select us.sequence_name
@@ -651,7 +652,7 @@ def has_primary_key?(table_name, owner = nil, desc_table_name = nil) # :nodoc:
       end
 
       def primary_keys(table_name) # :nodoc:
-        (_owner, desc_table_name) = @raw_connection.describe(table_name)
+        (_owner, desc_table_name) = _connection.describe(table_name)
 
         pks = select_values_forcing_binds(<<~SQL.squish, "SCHEMA", [bind_string("table_name", desc_table_name)])
           SELECT cc.column_name
@@ -696,7 +697,7 @@ def max_identifier_length
       alias index_name_length max_identifier_length
 
       def get_database_version
-        @raw_connection.database_version
+        _connection.database_version
       end
 
       def check_version
@@ -707,6 +708,10 @@ def check_version
         end
       end
 
+      private def _connection
+        @unconfigured_connection || @raw_connection
+      end
+
       class << self
         def type_map
           @type_map ||= Type::TypeMap.new.tap { |m| initialize_type_map(m) }
@@ -773,7 +778,7 @@ def extract_limit(sql_type) # :nodoc:
       end
 
       def translate_exception(exception, message:, sql:, binds:) # :nodoc:
-        case @raw_connection.error_code(exception)
+        case _connection.error_code(exception)
         when 1
           RecordNotUnique.new(message, sql: sql, binds: binds)
         when 60
diff --git a/spec/active_record/connection_adapters/oracle_enhanced/connection_spec.rb b/spec/active_record/connection_adapters/oracle_enhanced/connection_spec.rb
index 9171b958e..490d90a87 100644
--- a/spec/active_record/connection_adapters/oracle_enhanced/connection_spec.rb
+++ b/spec/active_record/connection_adapters/oracle_enhanced/connection_spec.rb
@@ -241,7 +241,7 @@ class ::Post < ActiveRecord::Base
     end
 
     after(:all) do
-      Object.send(:remove_const, "Post")
+      Object.send(:remove_const, "Post") if defined?(Post)
       ActiveRecord::Base.clear_cache!
     end
 
@@ -428,7 +428,7 @@ def lookup(path)
 
     before(:all) do
       ActiveRecord::Base.establish_connection(CONNECTION_PARAMS)
-      @conn = ActiveRecord::Base.connection.instance_variable_get("@raw_connection")
+      @conn = ActiveRecord::Base.connection.send(:_connection)
       @sys_conn = ActiveRecord::ConnectionAdapters::OracleEnhanced::Connection.create(SYS_CONNECTION_PARAMS)
       schema_define do
         create_table :posts, force: true