[dev] move_history_out_of_datatree.php script stalls

[Kevin M. Myer]

Wanted to report back my experience with converting to use the separate Horde
History table.

Start Sept 21, 10:03AM
End Sept 22, 4:49PM

Done. Migrated 42335 objects.

Some suggestions for consideration and documenting methodology:

1)  Echo something to the screen, notifying the user that this conversion may
take a very long time and that its normally to not see any activity for a
significant amount of time (up to and including days)
2)  Potential no-downtime migration scenario for Horde 3.0 -> 3.1 (comments
welcome as to whether or not this creates problems)
a) Create horde_histories table
b) Upgrade Horde_History to version that supports separate table
c) Configure Horde to use separate history table
d) Launch conversion script against datatree

In my thinking, this should allow production sites to remain online while
migrating.  From point 2b on, any new History that is created should end up in
the horde_histories table.  Meanwhile, the conversion is doing its thing,
datatree table is shrinking and newly migrated entries are being added to the
histories table.  Are there any locking issues that would come into 
play if the
database wasn't in a state of quiescence?  If this looks viable, I may test it
on my production site (above conversion was on a dump of production data, to a
test site).

Kevin

-- 
Kevin M. Myer
Senior Systems Administrator
Lancaster-Lebanon Intermediate Unit 13  http://www.iu13.org