[xwiki-users] Migrating 3.5 to 4.5.2

Hello, I'm trying migration of XWIki 3.5 to 4.5.2, and have some issues ... First, I must tell that I ran the queries described in [1], to cleanup the 3 stats tables. What happened though, is that during the migration I got an OutOfMemory error ... during migration of xwikistatsdoc. I relaunched with more heap (2Go), but got it again. I relaunched after activating safemode for that particular migration (R40000XWIKI6990), but then I got an issue on duplicate key for the xwikistatsdoc table: Caused by: com.xpn.xwiki.XWikiException: Error number 3005 in 3: R40000XWIKI6990 migration failed while converting ID from [232911443] to [7825842251281349221] A quick analysis of incriminated rows shows (sorry for display): +----------------------+------------+----------------------------+---------------+ | XWS_ID | XWS_NUMBER | XWS_NAME | XWS_CLASSNAME | +----------------------+------------+----------------------------+---------------+ | 232911443 | 1956069455 | Main | | | 5956685394971351254 | 1956069455 | | | | 7825842251281349221 | 1956069455 | Main | | +----------------------+------------+----------------------------+---------------+ To me it seems that as migration process was interrupted, maybe stat with id 232911443 was migrated successfully (in a previous run) to id 7825842251281349221, but old row was not removed. So when migration occurs again, it tries to migrate that same line again and fails. So I will try to run again after removing that line, but in case it fails, is it possible to only: - put back my backup of the 3 stats tables only (as the rest was successfully migrated) - relaunch the migration Would I need to update something in the migration temp tables to achieve that ? (ie restart migration only for stats tables), or will it do it by itself as it knows that step was unsuccessful ? Asking that because migration is painfully long, so I prefer to prepare myself to loose less time ... tomorrow ;-) Bonus question: There are plenty of rows in xwikistatsdoc with empty value in "XWS_NAME" field. Are these normal ? Can I / Should I purge them ? Br, Jeremie [1] http://jira.xwiki.org/browse/XWIKI-8129