297 - Data Loading Files Performance Problem

The migration scope has increased.
New source data has come into play and thus new mapping specifications have been made.

This has resulted in a really big data loading performance problem.
Our data transformation procedure is still fast, but the creation of the GIS loader files from the transformed data is starting to give us some headaches.

The GIS data loader has a flat file structure that is very verbose, the loading of each single value of each record is done through a 300 character text file line.
This means that a single database table row is transformed into, something like, the same number of text lines as the number of columns the row has. Plus the file and records header and footer structure.

As an example, house insurances data transformation is performed in around 4 hours, sequential time, and it generates about 184 millions of records. This is all performed in the transformation server.
These records are then exported into the GIS data loader file format from the Windows directly into the AS/400. This procedure is now taking much time, over 6 hours, sequentially, in the best case scenario.
This is obviously too much time, so we are exploring several hypotheses, ranging from creating a parallel file write process; writing the files locally, with and without compression, and transfer them via FTP to AS/400; cluster indexes with full coverage maintained in a different disk; splitting the database schemes across several disks.
Some of these techniques can, and will, be combined.

We have to tune the process from our side since there is not much the GIS or the AS/400 can do when it comes to massive data load tuning.
We are facing a lot of hard work in these next days.