EXreaction wrote:If your server supports MySQL fulltext searches then you can skip the search tables (which usually make up the far majority of the database size) when you backup and upgrade. Then after your done upgrading just make sure your search backend in phpBB3 is MySQL (and have it run the index option for it in the ACP).
actually, there is no way to tell phpbb2 to skip any specific table on backup, and the upgrade 2 => 3 does not use or touch these tables anyway.
once you're done upgrading, you need to either build those tables (ACP => Maintenance => Search Index) or build the mysql fulltext search index (same place).
as to using the fulltext mysql rather than the "fulltext native": the jury is still out regarding which of these options is worse. for small (< ~20K posts) forums it doesn't make much of a difference anyway, and for large forums neither is good enough (eg., phpbb.com uses neither, and instead uses a system called "sphinx").
both of them are pretty bad. in addition, fulltext-mysql implementation is about twice as bad as it really need to be, because olympus maintains three indexes (post-subject, post-contents, and post subject+content), where it should have maintained only two (topic title and post subject+content). this causes the index to be twice as large as it should have been, and posting and editing to be twice as slow as they should have been.
with the double-indexing, the db size using fulltext mysql is not much better than it is when using fulltext native.