Re: Detecting File Damage & Inconsistencies - Mailing list pgsql-hackers

From Simon Riggs
Subject Re: Detecting File Damage & Inconsistencies
Date
Msg-id CANP8+jJWOEk=dKBPgyiPzQdz+0EMRHyzB8szS_5e8H7oRND9Ww@mail.gmail.com
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In response to Re: Detecting File Damage & Inconsistencies  (Simon Riggs <simon@2ndquadrant.com>)
Responses Re: Detecting File Damage & Inconsistencies  (Masahiko Sawada <sawada.mshk@gmail.com>)
List pgsql-hackers
On Fri, 13 Nov 2020 at 11:24, Simon Riggs <simon@2ndquadrant.com> wrote:
>
> On Fri, 13 Nov 2020 at 00:50, tsunakawa.takay@fujitsu.com
> <tsunakawa.takay@fujitsu.com> wrote:
> >
> > From: Simon Riggs <simon@2ndquadrant.com>
> > > If a rogue user/process is suspected, this would allow you to identify
> > > more easily the changes made by specific sessions/users.
> >
> > Isn't that kind of auditing a job of pgAudit or log_statement = mod?  Or, does "more easily" mean that you find
pgAuditcomplex to use and/or log_statement's overhead is big?
 
>
> Well, I designed pgaudit, so yes, I think pgaudit is useful.
>
> However, pgaudit works at the statement level, not the data level. So
> using pgaudit to locate data rows that have changed is fairly hard.
>
> What I'm proposing is an option to add 16 bytes onto each COMMIT
> record, which is considerably less than turning on full auditing in
> pgaudit. This option would allow identifying data at the row level, so
> you could for example find all rows changed by specific sessions.
> Also, because it is stored in WAL it will show updates that might no
> longer exist in the database because the changed row versions might
> have been vacuumed away. So pgaudit will tell you that happened, but
> having extra info in WAL is important also.
>
> So thank you for the question because it has allowed me to explain why
> it is useful and important.

Patch attached to implement "wal_sessioninfo" option.

-- 
Simon Riggs                http://www.EnterpriseDB.com/

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