Thread: Re: pgsql: Generate backup manifests for base backups, and validatethem.
Re: pgsql: Generate backup manifests for base backups, and validatethem.
From
Peter Eisentraut
Date:
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. -- Peter Eisentraut http://www.2ndQuadrant.com/ PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services
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. -- Robert Haas EnterpriseDB: http://www.enterprisedb.com The Enterprise PostgreSQL Company
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