I am the one who converted http://chat.provida.com
from vBulletin to ASPPG. There was a tremendous performance increase and the new forums are running smoothly.
It took about 3 weeks to write and test the import routines because we also imported thousands of user photos to the gallery, and we had custom member fields on vBulletin which we brought over to ASPPG. We imported over 100,000 users and just under a million posts.
The only change to the ASPPG database was to increase the field size for the signature field in the members file and the stored proc that writes to it. This is because we had users with long sigs on VB - like 2000 characters. This wouldn't normally be a requirement in a conversion, so it's likely you won't need to make any changes to the database. That's good, so you can remain fully compatible with future ASPPG upgrades.
Once the import routines ran I used some of ASPPG's stored procs to re-index and clean things up. The hardest part of it was getting the sort order on the forums right, but even that wasn't difficult once I understood how the ASPPG sort works. Samuel was very helpful with that.
Here's a quick summary of what you have to do:
1) Clean up any duplicate VB user accounts.
2) If you want to prune any VB posts, now is the time to do it.
3) Import VB Forums to ASPPG
4) Import VB Users to ASPPG
5) Import VB Avatars to ASPPG
6) Import VB Custom Member Fields to ASPPG (if any)
7) Import VB member photos to ASPPG (if any) and if you have photo albums, import them to the ASPPG gallery.
8) Import VB Threads to ASPPG
9) Import VB Posts to ASPPG (Note: Threads and posts from VB both go to the ASPPG pgd_messages table. This causes some duplication because the Thread title in VB is the same as the first POST title. You have to write a routine to clean up the duplicate info unless you combine the thread and post importer into one routine.)
10) Update the forum sort order logic and run ASPPG Proc to rebuild it.
11) Clean up VB tags in posts. VB often uses simulated HTML tags like [font] that might or might not work in ASPPG. Some do some don't. You can use a string function to find and replace these. It can take a long time to run because string manipulation is slow and in our case we had almost a million posts to go through. You could build this into the post importer, but then it would take a long time to do the import. I ran it afterward, because it was not a critical item in the migration.
12) Turn on the full text search feature in ASPPG. This will greatly speed up your searches, especially if you have a ton of posts.
13) Rebuild the full text index
14) Run all ASPPG basic maintenance tasks (in the admin panel).
post edited by Samuel -