On 30 July 2013 10:42, Sven Van Caekenberghe <s...@stfx.eu> wrote: > Hi Yanni, > > On 30 Jul 2013, at 05:17, Yanni Chiu <ya...@rogers.com> wrote: > >> On 29/07/13 7:08 PM, Sven Van Caekenberghe wrote: >>> >>> The explanation for the slowdown must be in the PgV2 driver. >> >> The PgV2 protocol is described at: >> http://www.postgresql.org/docs/7.1/static/protocol-message-formats.html >> >> Have a glance at the "AsciiRow" and "BinaryRow" message formats. The driver >> reads the data off the socket, parsing the the data, as described as >> described by the message format. With the V2 protocol design, you have to >> read the result row, one field at a time. >> >> IIUC, in the newer V3? protocol, the AsciiRow/BinaryRow message is replaced >> by a DataRow message. The DataRow message has the message size included, >> which could allow the driver to read the entire set of fields for one data >> row, using a single socket read (or a few buffer sized reads). >> >> I recall seeing an experimental V3 protocol implementation, a few years back >> - sorry, no links handy. It would be nice to see some benchmarks. >> >> Hope that helps. > > Thanks for the response. > > I believe the V3 project is here http://www.squeaksource.com/PostgresV3.html. > > Now, I probably spoke too fast and should have taken Mariano's advice to > never speculate and first measure. Here is my quick test that, for me, shows > that PostgresV2 seems more than fast enough (something that I had experienced > before without doing benchmarks). > > [ self execute: 'select longitude,latitude from log_data limit 10000;' ] > timeToRun. > > => 76 ms > 76 ms for 10000 records? that's quite good throughput i would say.
> [ self execute: 'select longitude,latitude from log_data limit 100000;' ] > timeToRun. > > => 765 ms > > This is querying for 2 floats from a huge table, over the network. Pretty > fast ;-) > > So, back to Chris: what exactly are you doing that is (so) slow ? > > Anyway, thanks Yanni for all your work on the existing driver ! > > Sven > > -- > Sven Van Caekenberghe > Proudly supporting Pharo > http://pharo.org > http://association.pharo.org > http://consortium.pharo.org > > > > > -- Best regards, Igor Stasenko.
