-----Oprindelig meddelelse----- >Fra: Laurenz Albe <laurenz.albe@xxxxxxxxxxx> >Sendt: 20. september 2021 15:18 >Til: Niels Jespersen <NJN@xxxxxx>; pgsql-general@xxxxxxxxxxxxxx >Emne: Re: Possibilities for optimizing inserts across oracle_fdw foreign data wrapper > >On Sun, 2021-09-19 at 10:28 +0000, Niels Jespersen wrote: >> We are often using the oracle_fdw to transfer data between Postgres (version 11+) and Oracle (version 18+). It works great. >> >> However I have a task at hand that requires inserting a few billion rows in an Oracle table from a Postgres query. >> If I could make the Oracle insert direct load, that would usually also increase throughput. > But, is that possible here. There are no constraints defined on the destinaton tables. > >The cause of the bad performance for bulk data modifications is that the FDW API is built that way: each row INSERTed means a round trip between PostgreSQL and Oracle. > >That could be improved by collecting rows and inserting them in bulk on the Oracle side, but I don't feel like implementing that and complicating the code.> > >From my point of view, oracle_fdw is good for reading, but not for bulk writes. > >Yours, >Laurenz Albe Thank you for clairifying. I will use a python script for doing this, then. Read large chunks of data from Postgres and insert equally large chunks into Oracle, possibly using direct load. I know this can work. Regards Niels
