PG 10 logical replication version dependency?

[Colin 't Hart]

Hi,

Is there a version dependency when using logical replication? Do both
sides have to be running the same major version? Or is it a wire
protocol that will be backwards compatible in future releases?

I sincerely hope it's the latter so that users of this aren't forced
to upgrade all of their interconnected servers at the same time.

Thanks,

Colin

Redis 16 times faster than Postgres?

[Colin 't Hart]

Hi,

Can someone take a look at this blog post?
https://www.peterbe.com/plog/redis-vs-postgres-blob-of-json

Can Redis really be 16 times faster than Postgres? Surely Postgres can get
closer to the raw speed of the hardware than 1 order of magnitude?

Thanks,

Colin

Cancelling "vacuum full" in single user mode?

[Colin 't Hart]

Hi,

I have a customer approaching transaction wraparound, about 3million
transaction IDs away at the moment.
Postgres 9.5 (yes, I know...)

Somewhat mislead by the message to vacuum the database in single user
mode, they are now in single user mode and are running "vacuum full"
on the "worst" database, which has 18.5 million tables, and is about
350GB on disk.

Now we want to cancel the "vacuum full" and run a "vacuum freeze"
instead... or preferably, start back up in multiuser mode and run
vacuum there, but that was running very slowly while autovacuum was
trying to run (so we would need to disable that too, for now).

So,

1. Can we cancel safely?
2. Any other suggestions? Upgrade to a newer version right now?

/Colin

Cancelling "vacuum full" in single user mode?

[Colin 't Hart]

Hi,

I have a customer approaching transaction wraparound, about 3million
transaction IDs away at the moment.
Postgres 9.5 (yes, I know...)

Somewhat mislead by the message to vacuum the database in single user
mode, they are now in single user mode and are running "vacuum full"
on the "worst" database, which has 18.5 million tables, and is about
350GB on disk.

Now we want to cancel the "vacuum full" and run a "vacuum freeze"
instead... or preferably, start back up in multiuser mode and run
vacuum there, but that was running very slowly while autovacuum was
trying to run (so we would need to disable that too, for now).

So,

1. Can we cancel safely?
2. Any other suggestions? Upgrade to a newer version right now?

/Colin

Regression in Postgres 17?

[Colin 't Hart]

Hi,

This works in Postgres 15:

pg15> create function json_test(out value text, out json jsonb)
returns record
language sql
as
$$
  select null::text, null::jsonb;
$$
;
CREATE FUNCTION
pg15> select * from json_test();
┌───┬──┐
│ value │ json │
├───┼──┤
│   │  │
└───┴──┘
(1 row)


In Postgres 17 trying to create the function yields an error:

pg17> create function json_test(out value text, out json jsonb)
returns record
language sql
as
$$
  select null::text, null::jsonb;
$$
;
ERROR:  syntax error at or near "jsonb"
LINE 1: create function json_test(out value text, out json jsonb)


Am I doing something wrong? Or is this a regression?

Thanks,

Colin