Re: archive_timeout and WAL size

Thanks, Adrian.

That's the reference I was looking for.

Atenciosamente,

Edson Carlos Ericksson Richter

Em 29/06/2015 15:55, Adrian Klaver escreveu:
> On 06/29/2015 11:49 AM, Edson Richter wrote:
>> Dear community,
>>
>> I'm using PostgreSQL 9.3.6 on Linux x64.
>>
>> Would sound a stupid questions, and sorry if it was already asked
>> before: if I set the "archive_timeout", and then I have them sent every
>> minute (for example), are the files still 16MB in size, or are they
>> truncated and sent in smaller sizes as well?
>> I've not found this information in docs.
>
> See here:
>
> http://www.postgresql.org/docs/9.4/interactive/runtime-config-wal.html#RUNTIME-CONFIG-WAL-ARCHIVING
>
>
> "archive_timeout (integer)
>
> The archive_command is only invoked for completed WAL segments.
> Hence, if your server generates little WAL traffic (or has slack
> periods where it does so), there could be a long delay between the
> completion of a transaction and its safe recording in archive storage.
> To limit how old unarchived data can be, you can set archive_timeout
> to force the server to switch to a new WAL segment file periodically.
> When this parameter is greater than zero, the server will switch to a
> new segment file whenever this many seconds have elapsed since the
> last segment file switch, and there has been any database activity,
> including a single checkpoint. (Increasing checkpoint_timeout will
> reduce unnecessary checkpoints on an idle system.) Note that archived
> ^^^^^^^^^^^^^^^^^^
> files that are closed early due to a forced switch are still the same
> ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
> length as completely full files. Therefore, it is unwise to use a very
> ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
> short archive_timeout — it will bloat your archive storage.
> archive_timeout settings of a minute or so are usually reasonable. You
> should consider using streaming replication, instead of archiving, if
> you want data to be copied off the master server more quickly than
> that. This parameter can only be set in the postgresql.conf file or on
> the server command line.
> "
>>
>> Thanks,
>>
>
>