| From: | Robert Haas <robertmhaas(at)gmail(dot)com> |
|---|---|
| To: | Daniel Gustafsson <daniel(at)yesql(dot)se> |
| Cc: | Michael Paquier <michael(at)paquier(dot)xyz>, Magnus Hagander <magnus(at)hagander(dot)net>, Andres Freund <andres(at)anarazel(dot)de>, Tomas Vondra <tomas(dot)vondra(at)2ndquadrant(dot)com>, Alvaro Herrera <alvherre(at)2ndquadrant(dot)com>, PostgreSQL Developers <pgsql-hackers(at)lists(dot)postgresql(dot)org> |
| Subject: | Re: Online checksums patch - once again |
| Date: | 2020-01-20 20:14:47 |
| Message-ID: | CA+Tgmoa_WTE6WGn7P05TeOCRO82d+mVg+TaLSe0xjd56WhOQmA@mail.gmail.com |
| Views: | Raw Message | Whole Thread | Download mbox | Resend email |
| Thread: | |
| Lists: | pgsql-hackers |
On Sat, Jan 18, 2020 at 6:18 PM Daniel Gustafsson <daniel(at)yesql(dot)se> wrote:
> Thanks again for reviewing (and working on the infrastructure required for this
> patch to begin with)! Regarding the persisting the progress; that would be a
> really neat feature but I don't have any suggestion on how to do that safely
> for real use-cases.
Leaving to one side the question of how much work is involved, could
we do something conceptually similar to relfrozenxid/datfrozenxid,
i.e. use catalog state to keep track of which objects have been
handled and which not?
Very rough sketch:
* set a flag indicating that checksums must be computed for all page writes
* use barriers and other magic to make sure everyone has gotten the
memo from the previous step
* use new catalog fields pg_class.relhaschecksums and
pg_database.dathaschecksums to track whether checksums are enabled
* keep launching workers for databases where !pg_class.dathaschecksums
until none remain
* mark checksums as fully enabled
* party
--
Robert Haas
EnterpriseDB: http://www.enterprisedb.com
The Enterprise PostgreSQL Company
| From | Date | Subject | |
|---|---|---|---|
| Next Message | Alexander Kukushkin | 2020-01-20 20:17:47 | Re: Increase psql's password buffer size |
| Previous Message | Dean Rasheed | 2020-01-20 20:13:12 | Re: Greatest Common Divisor |