I was in the process of upgrading my installation from 1.15.0 to 1.16.0 this morning and I made a backup copy of the database using phpMyAdmin. I suspect that's not recommended and I can see why the instructions use mysqldump instead. Believe me, I'll do it the "right" way from now on. In any case, after upgrading the PHP and running update.php, the site wasn't working. I figured I'd restore the database and start over.
It turns out phpMyAdmin didn't do a very good job of exporting my database. I did manage to recreate my database from an older backup and then went through the phpMyAdmin dump table by table, since most of them seemed fine.
There were, it turns out, two problems, one more serious than the other.
First, in the categorylinks table, it didn't put single quotes around the dates for some reason. I was able to add them easily enough (regex replace is a godsend!).
The other problem was in the objectcache. For some reason, the contents of that are mostly giberish. The 'value' field in that table is a mediumblob but there are other tables with mediumblobs that didn't cause any problems. Is the content of that table different in some way that causes this problem?
Actually, while I'm interested in the above my real question is how serious is it that this table is now out of sync with the rest of the database? Obviously I've lost something but is it serious?
Hello,
After you placed the back-up back online did you run RebuildAll.php from the maintenance directory?
best,
On 7/28/2010 12:51 PM, Huib Laurens wrote:
Hello,
After you placed the back-up back online did you run RebuildAll.php from the maintenance directory?
I had not. I have now, although it didn't make any obvious difference. I should say that everything seems to be working properly again (still on 1.15.0 -- I'm a bit nervous now about the upgrade to 1.16.0).
One thing I notice is that the objectcache table seems to be non-readable in the file generated by mysqldump, as well. Is that table MEANT to be backed up?
On Wed, Jul 28, 2010 at 12:33 PM, Henry Hartley henry@dotrose.com wrote:
One thing I notice is that the objectcache table seems to be non-readable in the file generated by mysqldump, as well. Is that table MEANT to be backed up?
If it's a smallish wiki truncating the objectcache table should cause no problems without too bad a performance hit.
Dont quote me on that, YMMV, Standard Disclaimer, tc.
On 7/28/2010 1:36 PM, OQ wrote:
On Wed, Jul 28, 2010 at 12:33 PM, Henry Hartleyhenry@dotrose.com wrote:
One thing I notice is that the objectcache table seems to be non-readable in the file generated by mysqldump, as well. Is that table MEANT to be backed up?
If it's a smallish wiki truncating the objectcache table should cause no problems without too bad a performance hit.
All seems well -- the upgrade went fine the second time around.
Henry Hartley wrote:
One thing I notice is that the objectcache table seems to be non-readable in the file generated by mysqldump, as well. Is that table MEANT to be backed up?
No. The objectcache table is a cache of php objects commonly used (that's why you see binary). Just truncate it. It will slowly readd things there as they are used, which could have been retrieved for that cache, but that's all.
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