On Wed, Jul 8, 2015 at 11:37 AM, Andres Freund <and...@anarazel.de> wrote: > > On 2015-07-08 10:58:51 -0300, Fabrízio de Royes Mello wrote: > > Think in an ETL job that can be use an unlogged table to improve the load > > performance, but this job create a "large table" and to guarantee the data > > consistency you need to transform it into a regular table, and with the > > current implementation rewrite the entire heap, toast and indexes. > > Don't buy that. The final target relation will usually already have > content. Also everything but wal_level=minimal will force you to WAL log > the contents anyway.
If the "wal_level=minimal" we don't need to force the wal log of the contents. If the "wal_level != minimal" we need just to xlog all the pages, but in both cases we don't need the extra job to create a new datafiles and copy the contents between them. So we'll improve performance, or am I missing something? Regards, -- Fabrízio de Royes Mello Consultoria/Coaching PostgreSQL >> Timbira: http://www.timbira.com.br >> Blog: http://fabriziomello.github.io >> Linkedin: http://br.linkedin.com/in/fabriziomello >> Twitter: http://twitter.com/fabriziomello >> Github: http://github.com/fabriziomello
