On Wed, Jul 31, 2013 at 6:32 PM, Chris <cpmbai...@btinternet.com> wrote:
> It definitely seems to be because most things in the V2 driver are coming > in as strings and then being converted. Running the same query on the three > systems gives the following for a 65000 double array > > PGV2 770m/s > PGV3 200m/s > Psycopg2 130m/s > > Now I just need to find out how to get PGV3 as the backend for Glorp! > > PLease please please use the Glorp version you get from the DBX suite. You need to create a subclass of DatabaseDriver. You can take a look to NativePostgresDriver and create a similar one for V3. I would also like to have Glorp + PostgresV3 running. Also...we should somehow use NativePostgresPoolingDriver and NativePostgresConnectionPool for V3... we need some refactor here... We should join forces!! > Cheers > Chris > > > 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<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 <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 >> >> [ 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 >> >> >> >> >> >> >> > > -- Mariano http://marianopeck.wordpress.com
