Source Oracle

Airbyte's Oracle enterprise source connector offers the following features:

• Incremental as well as Full Refresh sync modes, providing flexibility in how data is delivered to your destination.
• Reliable replication at any table size with checkpointing and chunking of database reads.

The required minimum platform version is v0.58.0 for this connector.

Features

From the point of view of the Oracle database instance, the Enterprise Oracle source operates strictly in a read-only fashion.

Getting Started

Requirements

1. Oracle DB version 23ai, 21c or 19c.
2. Dedicated read-only Airbyte user with access to all tables needed for replication.

1. Make sure your database is accessible from the machine running Airbyte

This is dependent on your networking setup. The easiest way to verify if Airbyte is able to connect to your Oracle instance is by testing the connection in the UI.

2. If using CDC, make sure your database can run LogMiner and that supplemental logging is enabled for all relevant tables

Skip this step if you don't intend to perform CDC incremental syncs.

This connector relies on Debezium to perform CDC incremental syncs, and Debezium in turn relies on Oracle LogMiner. LogMiner is typically not enabled by default and requires some extra steps to enable. What form these steps take depends on whether the Oracle instance is managed via Amazon RDS or not.

In the case of an Amazon RDS instance, the steps are as follows:

1. Check that SELECT LOG_MODE FROM V$DATABASE returns ARCHIVELOG. If not, ensure that backups are enabled.
2. Execute exec rdsadmin.rdsadmin_util.set_configuration('archivelog retention hours',24), possibly replacing 24 with a more suitable value depending on the intended sync frequency. For instance, if the sync is intended to be run daily, then a retention period spanning multiple days is advisable.
3. Execute exec rdsadmin.rdsadmin_util.alter_supplemental_logging('ADD') to enable supplemental logging on the database.

In the case of any other Oracle instance, the steps are as follows:

1. CONNECT ... AS SYSDBA using SQL Plus or equivalent.
2. Provision the redo log files with something along the lines of ALTER SYSTEM SET db_recovery_file_dest_size = 10G and ALTER SYSTEM SET db_recovery_file_dest = '/opt/oracle/oradata/recovery_area' SCOPE=SPFILE but replacing the 10G and directory path arguments with suitable values. Note that the directory in the path needs to exist.
3. Shut down and restart the instance with SHUTDOWN IMMEDIATE and STARTUP MOUNT.
4. ALTER DATABASE ARCHIVELOG, ALTER DATABASE ADD SUPPLEMENTAL LOG DATA and ALTER DATABASE OPEN to restart the database with supplemental logging enabled.

At this point, RDS instance or not, all that remains to prepare the database for CDC incremental syncs is to enable supplemental logging on each of the relevant tables:

ALTER TABLE ... ADD SUPPLEMENTAL LOG DATA (ALL) COLUMNS;

If you need more help preparing the database, see Preparing the database in Debezium's docs.

3. Create a dedicated read-only user with access to the relevant tables

This step is optional but highly recommended to allow for better permission control and auditing. This step is even more highly recommended when performing CDC incremental syncs, as the user will require a very specific set of database privileges. Alternatively, you can use Airbyte with an existing user in your database.

To create a dedicated database user, run the following commands against your database:

CREATE USER airbyte IDENTIFIED BY <your_password_here>;
GRANT CREATE SESSION TO airbyte;

Next, grant the user read-only access to the relevant tables. The simplest way is to grant read access to all tables in the schema as follows:

GRANT SELECT ANY TABLE TO airbyte;

Or you can be more granular:

GRANT SELECT ON "<schema_a>"."<table_1>" TO airbyte;
GRANT SELECT ON "<schema_b>"."<table_2>" TO airbyte;

Your database user should now be ready for use with Airbyte, except for CDC incremental syncs.

4. If using CDC incremental syncs, grant your user extra permissions

Skip this step if you don't intend to perform CDC incremental syncs.

These requirements are driven by the connector's use of Debezium which in turn uses LogMiner.

GRANT FLASHBACK ANY TABLE TO airbyte;
GRANT SELECT ANY TABLE TO airbyte;
GRANT SELECT_CATALOG_ROLE TO airbyte;
GRANT EXECUTE_CATALOG_ROLE TO airbyte;
GRANT SELECT ANY TRANSACTION TO airbyte;
GRANT LOGMINING TO airbyte;
GRANT CREATE TABLE TO airbyte;
GRANT LOCK ANY TABLE TO airbyte;
GRANT CREATE SEQUENCE TO airbyte;

If the database instance is a multitenant CDB instance, then these grant statements need to be supplemented with the CONTAINER=ALL clause. Furthermore, an extra privilege is required:

GRANT SET CONTAINER TO airbyte CONTAINER=ALL;

The exact set of permissions varies depending on the Oracle database instance version.

5. Include the schemas Airbyte should look at when configuring the Airbyte Oracle Source

Case-sensitive. Defaults to the upper-cased user if empty. If the user does not have access to the configured schemas, no tables will be discovered and the connection test will fail.

Airbyte Cloud

On Airbyte Cloud, only secured connections to your Oracle instance are supported in source configuration. Note that while the connector is still incubating, this may not yet be actively enforced. You may configure your connection to either use SSL or an available encryption scheme, or by using an SSH tunnel.

Oracle encryption schemes

The connection to the Oracle database instance can be established using the following schemes:

1. Unencrypted connections will be made using the TCP protocol where all data over the network will be transmitted unencrypted. Airbyte Cloud will only allow this if an SSH tunnel is also used.
2. Native Network Encryption (NNE) gives you the ability to encrypt database connections without the configuration overhead of SSL / TLS and without the need to open and listen on different ports. In this case, the SQLNET.ENCRYPTION_CLIENT option will always be set as REQUIRED by default: the client or server will only accept encrypted traffic, but gives you the opportunity to choose an Encryption Algorithm according to the security policies you require.
3. TLS Encrypted (verify certificate) gives you the ability to encrypt database connections using the TLS protocol, taking into account the handshake procedure and certificate verification. To use this option, insert the content of the certificate issued by the server into the SSL PEM file field.

Connection to Oracle via an SSH Tunnel

Airbyte has the ability to connect to an Oracle instance via an SSH Tunnel. The reason you might want to do this because it is not possible (or against security policy) to connect to the database directly (e.g. it does not have a public IP address).

When using an SSH tunnel, you are configuring Airbyte to connect to an intermediate server (a.k.a. a bastion sever) that does have direct access to the database. Airbyte connects to the bastion and then asks the bastion to connect directly to the server.

Using this feature requires additional configuration, when creating the source. We will talk through what each piece of configuration means.

1. Configure all fields for the source as you normally would, except SSH Tunnel Method.

2. SSH Tunnel Method defaults to No Tunnel (meaning a direct connection). If you want to use an SSH Tunnel choose SSH Key Authentication or Password Authentication.

   1. Choose Key Authentication if you will be using an RSA private key as your secret for establishing the SSH Tunnel (see below for more information on generating this key).

   2. Choose Password Authentication if you will be using a password as your secret for establishing the SSH Tunnel.

3. SSH Tunnel Jump Server Host refers to the intermediate (bastion) server that Airbyte will connect to. This should be a hostname or an IP Address.

4. SSH Connection Port is the port on the bastion server with which to make the SSH connection. The default port for SSH connections is 22, so unless you have explicitly changed something, go with the default.

5. SSH Login Username is the username that Airbyte should use when connection to the bastion server. This is NOT the Oracle username.

6. If you are using Password Authentication, then SSH Login Username should be set to the password of the User from the previous step. If you are using SSH Key Authentication leave this blank. Again, this is not the Oracle password, but the password for the OS-user that Airbyte is using to perform commands on the bastion.

7. If you are using SSH Key Authentication, then SSH Private Key should be set to the RSA private Key that you are using to create the SSH connection. This should be the full contents of the key file starting with -----BEGIN RSA PRIVATE KEY----- and ending with -----END RSA PRIVATE KEY-----.

Generating an SSH Key Pair

The connector expects an RSA key in PEM format. To generate this key:

ssh-keygen -t rsa -m PEM -f myuser_rsa

This produces the private key in pem format, and the public key remains in the standard format used by the authorized_keys file on your bastion host. The public key should be added to your bastion host to whichever user you want to use with Airbyte. The private key is provided via copy-and-paste to the Airbyte connector configuration screen, so it may log in to the bastion.

Change Data Capture (CDC) limitations

The Enterprise Oracle source connector supports incremental syncs using CDC with some limitations. Some of these are readily apparent in the database and user setup steps described above:

• CDC availability is subject to a log retention period,
• CDC requires more user privileges,
• CDC requires supplemental logging and other settings at the Oracle instance level.

In addition to these, LogMiner, which our CDC relies on, has a few quirks:

• tables with names longer than 30 characters are simply ignored,
• columns with names longer than 30 characters are simply ignored.

Finally, LogMiner does not support all datatypes. See table below for details. If a type is not listed in the table, for instance any user-defined type such as a VARRAY, then it is not supported for CDC.

Data type mapping

Oracle data types are mapped to the following data types when synchronizing data.

Varray types are mapped to the corresponding Airbyte array type. This applies also to multiple levels of nesting, i.e. VARRAYs of VARRAYs, and so forth.

If you do not see a type in this list, assume that it is coerced into a string. We are happy to take feedback on preferred mappings.

Changelog

The connector is still incubating, this section only exists to satisfy Airbyte's QA checks.

• 0.0.1
• 0.0.2
• 0.0.3
• 0.0.4
• 0.0.5
• 0.0.6
• 0.0.7