Re: pgsql: Generate backup manifests for base backups, and validatethem.

On 4/7/20 12:44 PM, Robert Haas wrote:
> On Tue, Apr 7, 2020 at 5:51 AM Peter Eisentraut
> <peter.eisentraut@2ndquadrant.com> wrote:
>> On 2020-04-03 21:07, Robert Haas wrote:
>>> A new tool called pg_validatebackup can validate a backup against the
>>> manifest.
>>
>> In software engineering, "verify" and "validate" have standardized
>> distinct meanings.  I'm not going to try to explain them here, but you
>> can easily find them online.  I haven't formed an opinion on which one
>> of them this tool is doing, but I notice that both the man page and the
>> messages produced by the tool use the two terms seemingly
>> interchangeably.  We should try to pick the correct term and use it
>> consistently.
> 
> The tool is trying to make sure that we have the same backup that
> we're supposed to have, and that the associated WAL is present and
> sane. Looking at
> https://en.wikipedia.org/wiki/Verification_and_validation, that sounds
> more like verification than validation, but I confess that this
> distinction is new to me.

When I searched I found a two different definitions for validation and 
verification. One for software development (as in the link above and 
what I think Peter meant) and another for data (see 
https://en.wikipedia.org/wiki/Data_validation, 
https://en.wikipedia.org/wiki/Data_verification, 
https://www.differencebetween.com/difference-between-data-validation-and-vs-data-verification/)

It seems that validation vs. verify as defined in PMBOK (the former 
sense) does not really apply here, though. That leaves only the latter 
sense which appears less well-documented but points to "verify" as the 
better option.

Regards,
-- 
-David
david@pgmasters.net