The ideal solution depends on various questions, such as Oracle version, table size, query complexity, update frequency and developer’s technical capability. It is necessary to establish these metrics before defining the most appropriate solution.
For relatively small tables, I would program a dump in Mysql, exporting the data to a disk CSV. Oracle can directly read the CSV, without the need to import the data, through a resource called external table.
As Voce said that the application is "simple" and that Oracle searches for data in Mysql "from time to time", it seems to me that the above solution is suitable for a simple implementation.
As the time interval shortens and/or the volume of data increases, the external table solution may be inadequate. In such cases, a more appropriate solution would be the direct link between Oracle and Mysql.
Oracle has a feature called "Database Link", which allows a database (local) to execute SQL commands over another database (remote). When the local and remote Databases are both on Oracle, the process is very simple.
When the remote database is on another platform (in your case, Mysql), you need to set up an ODBC connection on the local server. Oracle can read data via ODBC and thus access Mysql in real time.
Remember, however, that connections via ODBC do not have the same scalability of native connections. Again, it depends on the volume of data and competitive queries.
I would create an ETL routine on Oracle to pull this data from time to time.
– gmsantos
What language is available for integration? Make a webservice.
– KaduAmaral