Re: Questions on Streaming Replication

> On 06/07/17 11:29, Wei Shan wrote:
>> Is it possible setup streaming replication between different OS?
>>
>> For example, between RHEL6 and RHEL7. I understand that it is not
>> possible between Windows and Linux.I need to migrate a PostgreSQL
>> instance to a new host, while upgrading the OS if possible.
>>
>> Has anyone done this before?

Mark Kirkwood wrote:
> I think you should be ok between different versions of Linux, provided:
>
> - both systems use hardware with same endianness and bitness (e.g both
> 64 bit Intel say)
>
> - both OS are the same bitness (e.g both 64 bit)

And, very importeant, if they don't have different versions of libc
that have different ideas about character collation.
See also https://www.postgresql.org/message-id/CB4D1C6BAA80CF146CB0D4F2%40eje.credativ.lan

RHEL6:

$ cat /etc/redhat-release
Red Hat Enterprise Linux Server release 6.9 (Santiago)
$ echo -e '156\n1-5-6\n110\n1-1-0' | LANG=de_DE.UTF-8 sort
1-1-0
110
1-5-6
156

RHEL7:

$ cat /etc/redhat-release
Red Hat Enterprise Linux Server release 7.3 (Maipo)
$ echo -e '156\n1-5-6\n110\n1-1-0' | LANG=de_DE.UTF-8 sort
110
1-1-0
156
1-5-6

So you are probably OK as long as you are only using the C collation, but
if you have any indexes that use a collation that is different on both systems,
The index on the standby will be corrupted.

Yours,
Laurenz Albe