Re: "Multiple table synchronizations are processed serially" still happens - Mailing list pgsql-hackers

From Amit Kapila
Subject Re: "Multiple table synchronizations are processed serially" still happens
Date
Msg-id CAA4eK1LJ=oL0P2nbKcHxeeu_3yajuenmgCKt-kdKyqgp2L7_Ng@mail.gmail.com
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In response to "Multiple table synchronizations are processed serially" still happens  (Guillaume Lelarge <guillaume@lelarge.info>)
Responses Re: "Multiple table synchronizations are processed serially" still happens
List pgsql-hackers
On Wed, Apr 28, 2021 at 2:43 PM Guillaume Lelarge
<guillaume@lelarge.info> wrote:
>
> And it logs the "still waiting" message as long as the first table is being synchronized. Once this is done, it
releasesthe lock, and the synchronization of the second table starts.
 
>
> Is there something I didn't understand on the previous thread?
>

It seems from a script that you are creating a subscription on the
same node as publication though in a different DB, right? If so, the
problem might be that copying the data of the first table creates a
transaction which blocks creation of the slot for second table copy.
The commit you referred will just fix the problem while reading the
data from the publisher not while writing data in the table in the
subscriber.

> I'd like to know why serial synchronization happens, and if there's a way to avoid it.
>

I guess you need to create a subscription on a different node.

-- 
With Regards,
Amit Kapila.



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