On Mon, Apr 21, 2014 at 8:03 PM, Torsten Förtsch
<torsten(dot)foertsch(at)gmx(dot)net>wrote:
> Hi,
>
> just out of curiosity, what's the difference between "streaming" and
> "catchup" state in pg_stat_replication.
>
> According to the documentation this field is "Current WAL sender state".
> But that does not tell me anything.
>
When a standby connects for the first time to a primary, it is not yet
synchronized, this is the "catchup" phase. Once the lag between the standby
and the master is reduced to zero for the first time, replication state
changes to "streaming".
--
Michael