Tomas Hlava wrote:
> there probably should be some mechanism for upgrades without forcing
> users to reset LiveSupport database - mainly when we change DB structure
> or add some default data.
> (I don't know about any suitable standard system for it.)
>
> My suggestions to solve it:
>
> 1st way (more similar to DB reset):
> - export DB to XML format
> - reinstall DB to new structure and insert default data
> - import data from XML file back to the DB
> (we probably need export/import anyway)
>
> 2nd way (IMO better, more complicated):
> There have to be some states of DB structure during development and
> "patches" for migration to next newer state.
> Example:
> - user have installed and started using LS of some version when DB
> structure is in state A
> - development continues to states B and C
> - with each new state is provided "patch" file for upgrade DB
> structure (ALTERs, UPDATEs)
> - user want to upgrade to new version (with DB state C)
> - there is stored info about state of DB structure somewhere
> in the LS (state A now)
> - after upgrade will be automatically aplied all remaining
> "patches" A->B, B->C
>
> Is it possible/usable ... ?
> Any ideas or comments are welcome.

while the first one is really simpler, it would require a total dump of
database contents when upgrading (might be a slow process, requiring a
lot of disk space). but then again, everyone running a serious system
should do regular backups

the second is more risky, and takes a lot more effort, IMHO. with risky
I mean that there might be the possiblity of data loss even, if the data
conversion fails somehow. so we'd have to suggest the users making a
backup anyway before doing an upgrade - so we're back to square 1...

------------------------------------------
Posted to Phorum via PhorumMail