[mythtv] MythTV life-cycle support intentions

Michael Watson michael at thewatsonfamily.id.au
Thu Aug 23 02:12:16 UTC 2012


On 23/08/2012 11:58 AM, Gary Buhrmaster wrote:
> On Thu, Aug 23, 2012 at 1:13 AM, Michael Watson
> <michael at thewatsonfamily.id.au> wrote:
> ....
>> Seems to me that, it would not be to difficult to write and import/export
>> script that either;
>>
>>      Exports all current recordings and relevant data since schema was change
>> (either automatically via date stored in database of when schema was updated
>> [if this data is even stored] or via a user entered date
>>      Imports routine would ignore any new data not required/used by previous
>> schema
> In some specific cases, perhaps.  But in other cases, the columns themselves
> get renamed, modified (in a specific way), or re-normalized (into other tables).
>
> Could one easily reverse some of those changes?  Sure.  Can one reverse
> others?  Not easily (if even possible(*)).  As with much else, one is free to
> create such a routine, and then closely follow the commit list and build
> the reversal into your routine.
>
> (btw, mysqldump already supports a --xml option, at least in recent versions.)
>
> Gary
>
> (*) A classic problem case is for tables where all rows where a column
> has a value "1" the column is changed to "2", but any "2"s are left as is.
> Which ones would need to be reversed?
>
For a rollback situation, I am thinking that it would only need to be 
concerned with recorded, and (possibly) oldrecorded tables.  I presume 
this is the only relevent data needed to be downgraded/imported after 
restoring backup from previous schema.. Music / Videos can be rescanned 
easily, and less likely to changed greatly have "testing/evaluating" 
newer version.

* Mind boggles as to why a 1 would become a 2, but a 2 would stay a 2.....





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