RE: Make default subscription streaming option as Parallel - Mailing list pgsql-hackers

From Hayato Kuroda (Fujitsu)
Subject RE: Make default subscription streaming option as Parallel
Date
Msg-id TYAPR01MB5692F83F3C7A383FD13A209CF57D2@TYAPR01MB5692.jpnprd01.prod.outlook.com
Whole thread Raw
List pgsql-hackers
Dear Vignesh,

> One key point to consider is that the lock on transaction objects will
> be held for a longer duration when using streaming in parallel. This
> occurs because the parallel apply worker initiates the transaction as
> soon as streaming begins, maintaining the lock until the transaction
> is fully completed. As a result, for long-running transactions, this
> extended lock can hinder concurrent access that requires a lock.

So, the current default is the most conservative and can run anywhere; your
proposal is a bit optimistic, right? Since long transactions should be avoided
in any case, and everyone knows it, I agree with your point.

One comment for your patch;
Shouldn't we add a streaming=off case for pg_dump test? You added lines but no one
passes it.

Best regards,
Hayato Kuroda
FUJITSU LIMITED

pgsql-hackers by date:

Previous
From: Guillaume Lelarge
Date:
Subject: Re: Add parallel columns for seq scan and index scan on pg_stat_all_tables and _indexes
Next
From: Alena Rybakina
Date:
Subject: Re: On disable_cost