Connecting to your Oracle DB instance

After Amazon RDS provisions your Oracle DB instance, you can use any standard SQL client application to connect to the DB instance. In this topic, you connect to a DB instance that is running the Oracle database engine by using Oracle SQL Developer or SQL*Plus.

For an example that walks you through the process of creating and connecting to a sample DB instance, see Creating an Oracle DB instance and connecting to a database on an Oracle DB instance.

Finding the endpoint of your Oracle DB instance

Each Amazon RDS DB instance has an endpoint, and each endpoint has the DNS name and port number for the DB instance. To connect to your DB instance using a SQL client application, you need the DNS name and port number for your DB instance.

You can find the endpoint for a DB instance using the Amazon RDS console or the Amazon CLI.

Console

Amazon CLI

To find the endpoint of an Oracle DB instance by using the Amazon CLI, call the describe-db-instances command.

aws rds describe-db-instances                                
                

"Endpoint": {
    "HostedZoneId": "Z1PVIF0B656C1W",
    "Port": 3306,
    "Address": "myinstance.123456789012.us-west-2.rds.amazonaws.com"
},    
                

Connecting to your DB instance using Oracle SQL developer

In this procedure, you connect to your DB instance by using Oracle SQL Developer. To download a standalone version of this utility, see the Oracle SQL developer downloads page.

To connect to your DB instance, you need its DNS name and port number. For information about finding the DNS name and port number for a DB instance, see Finding the endpoint of your Oracle DB instance.

Connecting to your DB instance using SQL*Plus

You can use a utility like SQL*Plus to connect to an Amazon RDS DB instance running Oracle. To download Oracle Instant Client, which includes a standalone version of SQL*Plus, see Oracle Instant Client Downloads.

To connect to your DB instance, you need its DNS name and port number. For information about finding the DNS name and port number for a DB instance, see Finding the endpoint of your Oracle DB instance.

sqlplus 'user_name@(DESCRIPTION=(ADDRESS=(PROTOCOL=TCP)(HOST=dns_name)(PORT=port))(CONNECT_DATA=(SID=database_name)))'                  
            

sqlplus user_name@(DESCRIPTION=(ADDRESS=(PROTOCOL=TCP)(HOST=dns_name)(PORT=port))(CONNECT_DATA=(SID=database_name)))             
            

SQL*Plus: Release 12.1.0.2.0 Production on Mon Aug 21 09:42:20 2017                
            

 SQL>               
            

Considerations for security groups

For you to connect to your DB instance, it must be associated with a security group that contains the necessary IP addresses and network configuration. Your DB instance might use the default security group. If you assigned a default, nonconfigured security group when you created the DB instance, the firewall prevents connections.

To create a new security group, security group that you create depends on the Amazon EC2 platform for your DB instance. To determine your platform, see Determining whether you are using the EC2-VPC or EC2-Classic platform. In general, if your DB instance is on the EC2-Classic platform, you create a DB security group; if your DB instance is on the VPC platform, you create a VPC security group. For information about creating a new security group, see Controlling access with security groups.

After you create the new security group, you modify your DB instance to associate it with the security group. For more information, see Modifying an Amazon RDS DB instance.

You can enhance security by using SSL to encrypt connections to your DB instance. For more information, see Oracle Secure Sockets Layer.

Considerations for process architecture

Server processes handle user connections to an Oracle DB instance. By default, the Oracle DB instance uses dedicated server processes. With dedicated server processes, each server process services only one user process. You can optionally configure shared server processes. With shared server processes, each server process can service multiple user processes.

You might consider using shared server processes when a high number of user sessions are using too much memory on the server. You might also consider shared server processes when sessions connect and disconnect very often, resulting in performance issues. There are also disadvantages to using shared server processes. For example, they can strain CPU resources, and they are more complicated to configure and administer.

For more information about dedicated and shared server processes, see About dedicated and shared server processes in the Oracle documentation. For more information about configuring shared server processes on an RDS for Oracle DB instance, see How do I configure Amazon RDS for Oracle database to work with shared servers? in the Knowledge Center.

Troubleshooting connections to your Oracle DB instance

The following are issues you might encounter when you try to connect to your Oracle DB instance.

For more information on connection issues, see Can't connect to Amazon RDS DB instance.

Modifying connection properties using sqlnet.ora parameters

The sqlnet.ora file includes parameters that configure Oracle Net features on Oracle database servers and clients. Using the parameters in the sqlnet.ora file, you can modify properties for connections in and out of the database.

For more information about why you might set sqlnet.ora parameters, see Configuring profile parameters in the Oracle documentation.

Setting sqlnet.ora parameters

Amazon RDS for Oracle parameter groups include a subset of sqlnet.ora parameters. You set them in the same way that you set other Oracle parameters. The sqlnetora. prefix identifies which parameters are sqlnet.ora parameters. For example, in an Oracle parameter group in Amazon RDS, the default_sdu_size sqlnet.ora parameter is sqlnetora.default_sdu_size.

For information about managing parameter groups and setting parameter values, see Working with parameter groups.

Supported sqlnet.ora parameters

Amazon RDS supports the following sqlnet.ora parameters. Changes to dynamic sqlnet.ora parameters take effect immediately.

The default value for each supported sqlnet.ora parameter is the Oracle default for the release. For information about default values for Oracle Database 12c, see Parameters for the sqlnet.ora file in the Oracle Database 12c documentation.

Viewing sqlnet.ora parameters

You can view sqlnet.ora parameters and their settings using the Amazon Web Services Management Console, the Amazon CLI, or a SQL client.

Viewing sqlnet.ora parameters using the console

For information about viewing parameters in a parameter group, see Working with parameter groups.

In Oracle parameter groups, the sqlnetora. prefix identifies which parameters are sqlnet.ora parameters.

Viewing sqlnet.ora parameters using the Amazon CLI

To view the sqlnet.ora parameters that were configured in an Oracle parameter group, use the Amazon CLI describe-db-parameters command.

To view the all of the sqlnet.ora parameters for an Oracle DB instance, call the Amazon CLI download-db-log-file-portion command. Specify the DB instance identifier, the log file name, and the type of output.

aws rds download-db-log-file-portion \
    --db-instance-identifier mydbinstance \
    --log-file-name trace/sqlnet-parameters \
    --output text

aws rds download-db-log-file-portion ^
    --db-instance-identifier mydbinstance ^
    --log-file-name trace/sqlnet-parameters ^
    --output text

Viewing sqlnet.ora parameters using a SQL client

After you connect to the Oracle DB instance in a SQL client, the following query lists the sqlnet.ora parameters.

SELECT * FROM TABLE
   (rdsadmin.rds_file_util.read_text_file(
        p_directory => 'BDUMP',
        p_filename  => 'sqlnet-parameters'));

For information about connecting to an Oracle DB instance in a SQL client, see Connecting to your Oracle DB instance.