pgsql: Remove pg_dump's --no-synchronized-snapshots switch.

Started by Tom Laneover 4 years ago2 messagescomitters
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#1Tom Lane
tgl@sss.pgh.pa.us

Remove pg_dump's --no-synchronized-snapshots switch.

Server versions for which there was a plausible reason to
use this switch are all out of support now. Leaving it
around would accomplish little except to let careless DBAs
shoot themselves in the foot.

Discussion: /messages/by-id/556122.1639520324@sss.pgh.pa.us

Branch
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master

Details
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https://git.postgresql.org/pg/commitdiff/2a712066d0587f65fcecd44e884dc6a09958dbdd

Modified Files
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doc/src/sgml/ref/pg_dump.sgml | 14 +-------------
src/bin/pg_dump/pg_backup.h | 1 -
src/bin/pg_dump/pg_dump.c | 11 ++---------
3 files changed, 3 insertions(+), 23 deletions(-)

#2Adrien Nayrat
adrien.nayrat@anayrat.info
In reply to: Tom Lane (#1)
Re: pgsql: Remove pg_dump's --no-synchronized-snapshots switch.

On 12/16/21 00:45, Tom Lane wrote:

Remove pg_dump's --no-synchronized-snapshots switch.

Server versions for which there was a plausible reason to
use this switch are all out of support now. Leaving it
around would accomplish little except to let careless DBAs
shoot themselves in the foot.

Discussion: /messages/by-id/556122.1639520324@sss.pgh.pa.us

Hello,

I have seen one situation where this option could have been useful even on
recent Postgres version:

Few years ago, I have seen an instance hit wraparound (1 million transactions
left) due to a bug (vacuum didn't freeze some blocks, bug has been fixed since).

I had to perform a dump/restore, but can't use parallel dump as Postgres refused
to export transaction snapshot. So the dump was ... long.

Late in the night, I didn't notice I could have used --no-synchronized-snapshots
to perform parallel dump. As Postgres didn't accept new transaction, there was
no risk of incoherent dump.

I don't know if we should keep this option. I just want to share a case where
this option could have been useful.

Regards,

--
Adrien