meaning of (to prevent wraparound) ..??

Hi Atul,

This means autovacuum is doing it’s job — most likely no need to be alarmed
here based on this alone. The autovacuum is helping avoid a txid limit.
This is part of PostgreSQL MVCC. You may check that section of the
documentation for more information on this.

On Wed, Nov 25, 2020 at 22:54 Atul Kumar <akumar14871@gmail.com> wrote:

Hi,

I have autovacuum running in background from last 30-40 minutes but I
noticed that it is with "(to prevent wraparound)" say for example
autovacuum: VACUUM trk.move (to prevent wraparound).

So what is the meaning of "(to prevent wraparound)" here ?

Will it impact the autovacuum anyhow ?

Please help me.

Regards,
Atul

--

Kind regards,
Jessica Sharp
---------------------
(469) 602-2363

Thanks Jessica. Could help me out by sharing documents that can help me
understand “to prevent wraparound “ in simplest way, postgres doc is little
bit harder for a newbee like me.

Regards
Atul

On Thursday, November 26, 2020, Jessica Sharp <jessica@thesharpgeek.com>
wrote:

Absolutely. This may be helpful:
https://youtu.be/bA1SgWn6Gv4

On Wed, Nov 25, 2020 at 23:09 Atul Kumar <akumar14871@gmail.com> wrote:

Thanks Jessica. Could help me out by sharing documents that can help me
understand “to prevent wraparound “ in simplest way, postgres doc is little
bit harder for a newbee like me.

Regards
Atul

On Thursday, November 26, 2020, Jessica Sharp <jessica@thesharpgeek.com>
wrote:

Hi Atul,

This means autovacuum is doing it’s job — most likely no need to be
alarmed here based on this alone. The autovacuum is helping avoid a txid
limit. This is part of PostgreSQL MVCC. You may check that section of the
documentation for more information on this.

On Wed, Nov 25, 2020 at 22:54 Atul Kumar <akumar14871@gmail.com> wrote:

Hi,

I have autovacuum running in background from last 30-40 minutes but I
noticed that it is with "(to prevent wraparound)" say for example
autovacuum: VACUUM trk.move (to prevent wraparound).

So what is the meaning of "(to prevent wraparound)" here ?

Will it impact the autovacuum anyhow ?

Please help me.

Regards,
Atul

--

Kind regards,
Jessica Sharp
---------------------
(469) 602-2363

--

Kind regards,
Jessica Sharp
---------------------
(469) 602-2363

On Wed, Nov 25, 2020 at 11:10:50PM -0700, Jessica Sharp wrote:

On Wed, Nov 25, 2020 at 23:09 Atul Kumar <akumar14871@gmail.com> wrote:

Thanks Jessica. Could help me out by sharing documents that can help me
understand “to prevent wraparound “ in simplest way, postgres doc is little
bit harder for a newbee like me.

Absolutely. This may be helpful:
https://youtu.be/bA1SgWn6Gv4

If you have any suggestions on how to improve this part of the docs,
please feel free:
https://www.postgresql.org/docs/devel/routine-vacuuming.html#VACUUM-FOR-WRAPAROUND

Note that due to the critical work that such vacuum jobs do, they
cannot be cancelled.
--
Michael