Re: Excel by XML generation

On Wed, Dec 16, 2020 at 9:56 AM Darren Strong <darren@xxxxxxxxx> wrote:

So, here is my current view of the state of Excel generation:

- There are lots of tools to take a file and create a spreadsheet, but, there isn't much flexibility in file dumps.
- There are languages like C, Python and Java that have pseudo native access to Excel generation through "libraries", but, I'm programming in RPG, so, I have to use inefficient interfaces to access those tools.

There's inefficient, and there's inefficient. The JNI-based POI
interface that most RPGers use is *especially* inefficient, because
there is overhead repeated for each Java method call.

If you take the approach of delegating ALL the workbook generation to
the other language, then you just have to make the one call.

It's true that on an IBM i, most other languages are not going to be
as fast as RPG. But they may be fast enough. Scott describes a big POI
job taking hours. Well, that's crazy-slow. Using Python (a notoriously
slow language), we generate workbooks that are in the 20 MB to 30 MB
range in about 15 minutes or so, and we have just about the weakest
machine possible to still be running 7.3. (Cache effects seem to be at
play, and the first run tends to be slower, later runs faster.)

John Y.