MariaDB / MySQL Adapter

This adapter allows mapping existing tables on a remote MariaDB oder MySQL 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.

Adapter Settings

The adapter has the following settings:

Setting	Description
host	The name or IP address of the remote MariaDB or MySQL instance.
port	The JDBC port number on the remote MariaDB or MySQL instance.
database	The name of the database containing the tables to be mapped.
username	The username to be used for authenticating at the remote MariaDB or MySQL instance.
password	The password to be used for authenticating at the remote MariaDB or MySQL instance.
maxConnections	The maximum number of concurrent JDBC connections.
transactionIsolation	Which level of transaction isolation should be used. Available options: SERIALIZABLE, READ_UNCOMMITTED, READ_COMMITTED, REPEATABLE_READ
tables	List of tables which should be imported. The names must to be separated by a comma.

Deployment

The adapter can either be deployed using the Polypheny-UI (Adapters -> Sources) or using the following SQL statement:

ALTER ADAPTERS ADD uniqueName 
   USING 'org.polypheny.db.adapter.jdbc.sources.MysqlSource' 
   WITH '{database:"polypheny",host:"localhost",maxConnections:"25",password:"polypheny",username:"polypheny",port:"3306",transactionIsolation:"SERIALIZABLE",tables:"foo,bar"}'

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:

ALTER TABLE tableName ADD COLUMN physicalName AS name

physicalName thereby refers to the column name on the remote database system.