Which frame do you refer to? On Mon, Sep 3, 2018 at 3:57 PM Dave Cramer <p...@fastcrypt.com> wrote:
> Not sure why reading from a socket is taking 1ms ? > > Dave Cramer > > da...@postgresintl.com > www.postgresintl.com > > > On Mon, 3 Sep 2018 at 09:39, Mate Varga <m...@matevarga.net> wrote: > >> Hi, >> >> https://imgur.com/a/ovsJPRv -- I've uploaded the profiling info (as an >> image, sorry). It seems this is a JDBC-level problem. I understand that the >> absolute timing is not meaningful at all because you don't know how large >> the resultset is, but I can tell that this is only a few thousands rows + >> few thousand largeobjects, each largeobject is around 1 kByte. (Yes I know >> this is not a proper use of LOBs -- it's a legacy db structure that's hard >> to change.) >> >> Thanks. >> Mate >> >> On Mon, Sep 3, 2018 at 11:52 AM Mate Varga <m...@matevarga.net> wrote: >> >>> Hey, >>> >>> we'll try to test this with pure JDBC versus hibernate. Thanks! >>> >>> >>> On Mon, Sep 3, 2018 at 11:48 AM Dave Cramer <p...@fastcrypt.com> wrote: >>> >>>> >>>> >>>> On Mon, 3 Sep 2018 at 03:55, Mate Varga <m...@matevarga.net> wrote: >>>> >>>>> 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. >>>>> >>>> >>>> Ah, so hibernate is in the mix. I wonder if that is causing some >>>> challenges ? >>>> >>>> >>>>> 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. >>>>> >>>>> Any chance you could write a simple non-hibernate test code to time >>>> the code ? >>>> >>>> Dave Cramer >>>> >>>> dave.cra...@crunchydata.ca >>>> www.crunchydata.ca >>>> >>>> >>>> >>>>> 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 >>>>>> >>>>>
