Обсуждение: Re: [PERFORM] [BUGS] Invalid WAL segment size. Allowed values are 1,2,4,8,16,32,64

On Fri, Jun 9, 2017 at 10:55 PM, Cocco Gianfranco
<Gianfranco.Cocco@eng.it> wrote:
> Is there a way to fix “wal_segsize” to about 1 Gb in 9.2. version, and “rebuild” postgreSQL server?

As long as you are able to compile your own version of Postgres and
your distribution does not allow that, there is nothing preventing you
to do so.

> The goal is to drastically reduce the number of WALs.
> Upgrading to 9.5, is the only way to fix this issue?

Note that a server initialized with a segment size of X won't work
with a binary compiled with a size of Y. But you can always take a
logical dump of the server before the upgrade, and reload it in the
version of the server with a larger segment size. The cost here is
more downtime.
--
Michael

On Tue, Jun 13, 2017 at 2:27 AM, Jeff Janes <jeff.janes@gmail.com> wrote:
> But there is something preventing it.  wal_segsize cannot exceed 64MB in
> 9.2. v10 will be the first version which will allow sizes above 64MB.

Yes, indeed. I have misread --with-segsize and --with-wal-segsize in
the docs. Sorry for the confusion.
--
Michael

On Tue, Jun 13, 2017 at 6:10 PM, Cocco Gianfranco
<Gianfranco.Cocco@eng.it> wrote:
> If I understand it well, we can build a new postgreSQL server, by setting
> this value into "configure" file?
>
> --with-wal-segsize=SEGSIZE   becomes  --with-wal-segsize=1024  ??

Yes, but as Jeff has pointed out upthread, this value can just go up
to 64 when using 9.5.
--
Michael

On Tue, Jun 13, 2017 at 10:39 PM, Cocco Gianfranco
<Gianfranco.Cocco@eng.it> wrote:
> ./configure --with-wal-segsize=1024
>
> checking for WAL segment size... configure: error: Invalid WAL segment size.
> Allowed values are 1,2,4,8,16,32,64.
>
> Please, how can I do?

When trying to compile Postgres 9.6, the maximum value is 64. If you
want to allow 1GB of WAL segment size you will need to wait for 10, or
just use 64MB.
--
Michael