Upgrade/Downgrade

On 23 August 2018 12:51:08 CEST, Sonam Sharma <sonams1209@gmail.com> wrote:

Hello,

My postgres version is 10.4 and I want to downgrade it to 9.5.
and one is at 9.2 and need to upgrade it to 9.5.
Can someone please help how to do this.
Unable to find anything online

Why downgrade? Dump and restore should do the job, have you tried it?

Regards, Andreas

--
2ndQuadrant - The PostgreSQL Support Company

No, I didn't. The version is not compatible with application, so need to
downgrade it

On Thu, Aug 23, 2018, 4:56 PM Andreas Kretschmer <andreas@a-kretschmer.de>
wrote:

On 23/08/2018 14:30, Sonam Sharma wrote:

No, I didn't. The version is not compatible with application, so need to downgrade it

Have you tried to tweak postgresql.conf ?
What do you mean is not compatible? What's the problem?

On Thu, Aug 23, 2018, 4:56 PM Andreas Kretschmer <andreas@a-kretschmer.de <mailto:andreas@a-kretschmer.de>> wrote:

On 23 August 2018 12:51:08 CEST, Sonam Sharma <sonams1209@gmail.com <mailto:sonams1209@gmail.com>> wrote:

Hello,

My postgres version is 10.4 and I want to downgrade it to 9.5.
and one is at 9.2 and need to upgrade it to 9.5.
Can someone please help how to do this.
Unable to find anything online

Why downgrade? Dump and restore should do the job, have you tried it?

Regards, Andreas

--
2ndQuadrant - The PostgreSQL Support Company

--
Achilleas Mantzios
IT DEV Lead
IT DEPT
Dynacom Tankers Mgmt

On Thu, 23 Aug 2018 14:47:25 +0300
Achilleas Mantzios <achill@matrix.gatewaynet.com> wrote:

What do you mean is not compatible? What's the problem?

As I recall there's several SETs and some other stuff that v.10 spits out that earlier versions do not recognize. Nothing that a little sed script can't fix but you need to understand what you're doing.

--
Dmitri Maziuk <dmaziuk@bmrb.wisc.edu>

On 08/23/2018 04:47 AM, Achilleas Mantzios wrote:

On 23/08/2018 14:30, Sonam Sharma wrote:

No, I didn't. The version is not compatible with application, so need
to downgrade it

Have you tried to tweak postgresql.conf ?
What do you mean is not compatible? What's the problem?

My guess would be that they have a vendor supported application that is
*only* supported on 9.5. I run into this more often than I like.

JD

--
Command Prompt, Inc. || http://the.postgres.company/ || @cmdpromptinc
*** A fault and talent of mine is to tell it exactly how it is. ***
PostgreSQL centered full stack support, consulting and development.
Advocate: @amplifypostgres || Learn: https://postgresconf.org
***** Unless otherwise stated, opinions are my own. *****

On Thu, Aug 23, 2018 at 11:44 AM Joshua D. Drake <jd@commandprompt.com>
wrote:

On 08/23/2018 04:47 AM, Achilleas Mantzios wrote:

On 23/08/2018 14:30, Sonam Sharma wrote:

No, I didn't. The version is not compatible with application, so need
to downgrade it

Have you tried to tweak postgresql.conf ?
What do you mean is not compatible? What's the problem?

My guess would be that they have a vendor supported application that is
*only* supported on 9.5. I run into this more often than I like.

Same story.

I suppose it's related (at least partially) xlog->wal and
**_location->**_lsn renamings in function names (full list made in Postgres
10:
https://wiki.postgresql.org/wiki/New_in_postgres_10#Renaming_of_.22xlog.22_to_.22wal.22_Globally_.28and_location.2Flsn.29
)
Those 10's changes are really painful.

I wish there were be some grace period, say 2-3 years, when both pg*_xlog_*
function names would also work as aliases for pg*_wal_**.

BTW, if the reason of downgrading is really related only these renamings,
it might be less stressful just to create function aleases, like:

create function pg_catalog.pg_last_xlog_receive_location() returns pg_lsn
as $$
select pg_current_wal_lsn();
$$ language sql;

+ granting proper permissions to specified DB roles, where needed.

Of course, it's hacky and should be only as a temporary solution until the
app is adjusted to support Postgres 10+.
But it gives an ability to have all good things added to Postgres 9.6 and
10.

On 23/08/2018 22:40, Nikolay Samokhvalov wrote:

On Thu, Aug 23, 2018 at 11:44 AM Joshua D. Drake <jd@commandprompt.com <mailto:jd@commandprompt.com>> wrote:

On 08/23/2018 04:47 AM, Achilleas Mantzios wrote:

On 23/08/2018 14:30, Sonam Sharma wrote:

No, I didn't. The version is not compatible with application, so need
to downgrade it

Have you tried to tweak postgresql.conf ?
What do you mean is not compatible? What's the problem?

My guess would be that they have a vendor supported application that is
*only* supported on 9.5. I run into this more often than I like.

Same story.

I suppose it's related (at least partially) xlog->wal and **_location->**_lsn renamings in function names (full list made in Postgres 10:
https://wiki.postgresql.org/wiki/New_in_postgres_10#Renaming_of_.22xlog.22_to_.22wal.22_Globally_.28and_location.2Flsn.29)
Those 10's changes are really painful.

I wish there were be some grace period, say 2-3 years, when both pg*_xlog_* function names would also work as aliases for pg*_wal_**.

yes this is true for scripts, monitoring, but for app? I doubt many apps depend on wal/lsn related functions.

BTW, if the reason of downgrading is really related only these renamings, it might be less stressful just to create function aleases, like:

create function pg_catalog.pg_last_xlog_receive_location() returns pg_lsn as $$
  select pg_current_wal_lsn();
$$ language sql;

+ granting proper permissions to specified DB roles, where needed.

Of course, it's hacky and should be only as a temporary solution until the app is adjusted to support Postgres 10+.
But it gives an ability to have all good things added to Postgres 9.6 and 10.

--
Achilleas Mantzios
IT DEV Lead
IT DEPT
Dynacom Tankers Mgmt