Re: Migration from 7.31 to 9.40

Colin Dawson said: > > As it's a slow news day I'll ask about migrations. > > I'm testing migrating from 7.31 to 9.40, the upgrade works fines and takes > around 5 mins to convert everything. The migration plan says to run > onchecks > (-cc, -cD, -cI, -cc, -ce) before and after. As these take quite some time > to > complete, a -cI took 8hrs 25mins for one table with 2 indexes and 290M > rows > how can I improve the runtimes for these checks so I don't end up taking > two > days to perform the migration? I don't think you can. I would just kick off the various onchecks well in advance and get them out of the way. Similarly, unless anything went blatantly wrong during the upgrade, I'd let users on to the system before the post-upgrade onchecks completed. I don't know how much value you might get out of backing up production, restoring it to another box and then running the onchecks on that. > Overall DB size is approx 320Gb. Several tables have 100M+ rows. RI is > used > throughout the DB so there are some tables with a number of indexes. I guess UPDATE STATISTICS might take a while, then? :o) Remember to check out the new usage of DBUPSPACE to help speed this up. Another *unsupported* trick is to upgrade your new copy instance, do the appropriate UPDATE STATISTICS, unload sysdistrib, upgrade production and then just delete from sysdistrib and import the unloaded distributions. Tech Support will be entitled to just laugh in your face if you do this and have a problem, however. :o) Don't forget to get rid of any outstanding in-place alters, as well. On a recent migration, I found it quicker to just update every row in every table than to work out which tables needed updating. Good luck! ;o) -- Bye now, Obnoxio "C'est pas parce qu'on n'a rien ' dire qu'il faut fermer sa gueule" - Coluche A smile is a gift that is free to the giver and precious to the recipient. But giving someone the finger is free too, and I find it more personal and sincere. sending to informix-list