Thanks a lot for your advice. I found the difference: My Java program sends one huge SQL string containing 1000 INSERT statements separated by ';' (without using prepared statements at all!), whereas my C++ program sends one INSERT statement with parameters to be prepared and after that 1000 times parameters. Now I refactured my C++ program to send also 1000 INSERT statements in one call to PQexec and reached the same performance as my Java program. I just wonder why anyone should use prepared statements at all? > -----UrsprÃngliche Nachricht----- > Von: pgsql-performance-owner@xxxxxxxxxxxxxx [mailto:pgsql-performance- > owner@xxxxxxxxxxxxxx] Im Auftrag von Richard Huxton > Gesendet: Donnerstag, 16. Dezember 2010 13:15 > An: Werner Scholtes > Cc: Divakar Singh; pgsql-performance@xxxxxxxxxxxxxx > Betreff: Re: performance libpq vs JDBC > > On 16/12/10 09:21, Werner Scholtes wrote: > > I assume that the wire protocol of PostgreSQL allows to transmit > > multiple rows at once, but libpq doesn't have an interface to access > it. > > Is that right? > > Sounds wrong to me. The libpq client is the default reference > implementation of the protocol. If there were large efficiencies that > could be copied, they would be. > > Anyway - you don't need to assume what's in the protocol. It's > documented here: > http://www.postgresql.org/docs/9.0/static/protocol.html > > I'd stick wireshark or some other network analyser on the two sessions > - > see exactly what is different. > > -- > Richard Huxton > Archonet Ltd > > -- > Sent via pgsql-performance mailing list (pgsql- > performance@xxxxxxxxxxxxxx) > To make changes to your subscription: > http://www.postgresql.org/mailpref/pgsql-performance -- Sent via pgsql-performance mailing list (pgsql-performance@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-performance
