Basically there's a class with a byte[] field, the class is mapped to table T and the byte field is annotated with @Lob so it goes to the pg_largeobject table. The DB is on separate host but relatively close to the app, and I can reproduce the problem locally as well. One interesting bit is that turning of SSL between the app and PSQL speeds up things by at least 50%.
Ah, one addition -- the binary objects are encrypted, so their entropy is very high. Mate On Sun, Sep 2, 2018 at 12:55 AM Dave Cramer <p...@fastcrypt.com> wrote: > > > > On Fri, 31 Aug 2018 at 10:15, Mate Varga <m...@matevarga.net> wrote: > >> I see -- we could try that, though we're mostly using an ORM (Hibernate) >> to do this. Thanks! >> >> On Fri, Aug 31, 2018 at 3:57 PM Dmitry Igrishin <dmit...@gmail.com> >> wrote: >> >>> пт, 31 авг. 2018 г. в 16:35, Mate Varga <m...@matevarga.net>: >>> > >>> > Hi, >>> > >>> > we're fetching binary data from pg_largeobject table. The data is not >>> very large, but we ended up storing it there. If I'm copying the data to a >>> file from the psql console, then it takes X time (e.g. a second), fetching >>> it through the JDBC driver takes at least 10x more. We don't see this >>> difference between JDBC and 'native' performance for anything except >>> largeobjects (and bytea columns, for the record). >>> > >>> > Does anyone have any advice about whether this can be tuned or what >>> the cause is? >>> I don't know what a reason of that, but I think it's reasonable and >>> quite simple to call lo_import()/lo_export() via JNI. >>> >> > Can't imagine that's any faster. The driver simply implements the protocol > > Do you have any code to share ? Any other information ? > > Is the JDBC connection significantly further away network wise ? > > > Dave Cramer > > da...@postgresintl.com > www.postgresintl.com >
