On 07/11/2018 04:10 PM, Christopher Browne wrote:
[snip]
> ITIL surely does NOT specify the use of database rollback scripts as
> THE SPECIFIED MECHANISM for a backout procedure.
>
> In practice, we tend to take database snapshots using filesystem
> tools, as that represents a backout procedure that will work regardless
> of the complexity of an upgrade.
>
> It is quite possible for an upgrade script to not be reversible.
>
> After all, not all matrices are invertible; there are a surprisingly large
> number of preconditions that are required for that in linear algebra.
>
> And in databases, not all upgrades may be reversed via rollback scripts.
Does "rollback script" truly mean undoing what you just did in a
transaction-like manner?
--
Angular momentum makes the world go 'round.