The PostgreSQL adapter allows mapping existing tables on a remote PostgreSQL database into the schema of Polypheny-DB. One adapter can map multiple tables. This allows push-down of larger portions of a query. While the schema must be static and cannot be changed with Polypheny-DB, the data on the remote tables can be updated independently of Polypheny-DB. Polypheny-DB connects to the remote database system as a client and providing full support for transactions.
The PostgreSQL adapter has the following settings:
|host||The name or IP address of the remote PostgreSQL instance.|
|port||The JDBC port number on the remote PostgreSQL instance.|
|database||The name of the database containing the tables to be mapped.|
|username||The username to be used for authenticating at the remote PostgreSQL instance.|
|password||The password to be used for authenticating at the remote PostgreSQL instance.|
|maxConnections||The maximum number of concurrent JDBC connections.|
|transactionIsolation||Which level of transaction isolation should be used. Available options: |
|tables||A list of tables which should be imported. The name must be in the format |
The adapter can either be deployed using the Polypheny-UI (Adapters -> Sources) or using the following SQL statement:
Please make sure to adjust the settings according to your needs.
After the deployment, the specified tables are mapped into the public schema of Polypheny-DB. The tables and columns can be renamed. Furthermore, columns can be reordered and dropped (this is handled virtually; schema modifications are not forwarded to the remote database system). Dropped columns can be added again using the Polypheny-UI or the following SQL statement:
physicalName thereby refers to the column name on the remote database system.