Im glad you are considering changing to phptimeseries or possibly phpfina and that it potentially solves a specific problem for you with the hosting.
The format of the phptimeseries data files is exactly the same as the mysql feeds (in terms of the binary structure) hence why phptimeseries still has the .MYD extension. I initially made use of that on emoncms.org to just switch GB’s of data over to phptimeseries without requiring a conversion process, just a command line file move and then changing the engine field in the feeds table.
It looks like that archived conversion script goes through the mysql data row by row so does not make use of that potentially very fast switch over but perhaps it is suitable for your hosting configuration if you do not have file level access to the mysql data?
As that script is archived I’m not sure if it will still work now, so it’s probably worth proceeding carefully.
If you have data recorded at a fixed interval and the data completeness is >50% you will save disk space with phpfina. PHPFina is also quite a bit faster on the visualisation side (as it doesnt require a binary search algorithm) and I’ve focused more of my development time around that engine in terms of some of the other capabilities in emoncms like postprocessing or the sync module.
I do have some significant changes in the pipeline that bring some of the benefits of phpfina to phptimeseries such as on the fly averaging and full support for timezone aligned data requests. I hope to get back to that development soon.
Let me know if you are able to access the mysql data files directly