title: Migrate from Oracle to MySQL
body: <p>We ran into serious performance problems with our Oracle database and we would like to try to migrate it to a MySQL-based database (either MySQL directly or, more preferably, Infobright).</p>
  
  <p>The thing is, we need to let the old and the new system overlap for at least some weeks if not months, before we actually know, if all the features of the new database match our needs.</p>
  
  <p>So, here is our situation:</p>
  
  <p>The Oracle database consists of multiple tables with each millions of rows. During the day, there are literally thousands of statements, which we cannot stop for migration.</p>
  
  <p>Every morning, new data is imported into the Oracle database, replacing some thousands of rows. Copying this process is not a problem, so we could, in theory, import in both databases in parallel.</p>
  
  <p>But, and here the challenge lies, for this to work we need to have an export from the Oracle database with a consistent state from one day. (We cannot export some tables on Monday and some others on Tuesday, etc.) This means, that at least the export should be finished in less than one day.</p>
  
  <p>Our first thought was to dump the schema, but I wasn't able to find a tool to import an Oracle dump file into MySQL. Exporting tables in CSV files might work, but I'm afraid it could take too long.</p>
  
  <p>So my question now is: </p>
  
  <p>What should I do? Is there any tool to import Oracle dump files into MySQL? Does anybody have any experience with such a large-scale migration?</p>
  
  <p>PS: Please, don't suggest performance optimization techniques for Oracle, we already tried a lot :-)</p>
  
  <p><em>Edit:</em> We already tried some ETL tools before, only to find out, that they were not fast enough: Exporting only one table already took more than 4 hours ... </p>
  
  <p><strong>2nd Edit:</strong> Come on folks ... did nobody ever try to export a whole database as fast as possible and convert the data so that it can be imported into another database system?</p>