On Wed, May 31, 2023 at 09:14:20AM +1200, David Rowley wrote: > On Wed, 31 May 2023 at 08:54, Ron <ronljohnsonjr@xxxxxxxxx> wrote: > > https://www.postgresql.org/about/news/postgresql-16-beta-1-released-2643/ > > says "PostgreSQL 16 can also improve the performance of concurrent bulk > > loading of data using COPY up to 300%." > > > > Since pg_dump & pg_restore use COPY (or something very similar), will the > > speed increase translate to higher speeds for those utilities? > > I think the improvements to relation extension only help when multiple > backends need to extend the relation at the same time. pg_restore can > have multiple workers, but the tasks that each worker performs are > only divided as far as an entire table, i.e. 2 workers will never be > working on the same table at the same time. So there is no concurrency > in terms of 2 or more workers working on loading data into the same > table at the same time. > > It might be an interesting project now that we have TidRange scans, to > have pg_dump split larger tables into chunks so that they can be > restored in parallel. Uh, the release notes say: <!-- Author: Andres Freund <andres@xxxxxxxxxxx> 2023-04-06 [00d1e02be] hio: Use ExtendBufferedRelBy() to extend tables more eff Author: Andres Freund <andres@xxxxxxxxxxx> 2023-04-06 [26158b852] Use ExtendBufferedRelTo() in XLogReadBufferExtended() --> <listitem> <para> Allow more efficient addition of heap and index pages (Andres Freund) </para> </listitem> There is no mention of concurrency being a requirement. Is it wrong? I think there was a question of whether you had to add _multiple_ blocks ot get a benefit, not if concurrency was needed. This email about the release notes didn't mention the concurrent requirement: https://www.postgresql.org/message-id/20230521171341.jjxykfsefsek4kzj%40awork3.anarazel.de While the case of extending by multiple pages improved the most, even extending by a single page at a time got a good bit more scalable. Maybe just "Improve efficiency of extending relations"? -- Bruce Momjian <bruce@xxxxxxxxxx> https://momjian.us EDB https://enterprisedb.com Only you can decide what is important to you.
