Re: Slow performance with 9.3-110x JDBC 4

In order to get to the root cause of this I'd have to see exactly what you
are doing ?

Can you share the relevant code ?

Dave Cramer

dave.cramer(at)credativ(dot)ca
http://www.credativ.ca

On Fri, Mar 28, 2014 at 6:25 AM, ChatPristi <cchristo_0899(at)yahoo(dot)fr> wrote:

> Thank you very much for your help and explanations.
>
> Indeed, the Lachezar's recommendation (jdbc:postgresql://localhost/database?protocolVersion=2) restores the speed:
> 190413 ms with jdbc-9.3.1101 and postgresql 9.3.4.
>
> As I used bytea and due to change since postgresql 9.0 for handling them
> (bytea_output parameter), my programs only work with jdbc-9.3.1101 (and
> no longer with jdbc-8.4-703).
>
> So, I must use 9.3.1101. However, what does the sentence "I was
> recommending that for testing purposes only" by Lachezar means ? How to
> increase performance of server side prepared statements ?
>
>
>
> Le Vendredi 28 mars 2014 10h50, Lachezar Dobrev <l(dot)dobrev(at)gmail(dot)com> a
> écrit :
> For the record: I was recommending that for testing purposes only, to
> check if the reduced performance is related to protocol version (I believe
> there is a significant change it might).
>
>
> 2014-03-27 21:52 GMT+02:00 Dave Cramer <davecramer(at)gmail(dot)com>:
>
> I wanted to avoid that recommendation, but since it is out there.
> protocolVersion reverts to the same protocol as 8.4 uses which does not use
> server side prepared statements
>
> And I would expect it to speed up, or at least be the same as 8.4.7
>
> Dave
>
> www.credativ.ca
>
>
> On Thu, Mar 27, 2014 at 1:45 PM, Edson Richter <edsonrichter(at)hotmail(dot)com>wrote:
>
> Em 27/03/2014 13:58, Lachezar Dobrev escreveu:
>
> You might want to do the same tests after adding ?protocolVersion=2
> to the connection URL.
> i.e.:
> jdbc:postgresql://localhost/database?protocolVersion=2
>
> 2014-03-27 15:35 GMT+02:00 ChatPristi <cchristo_0899(at)yahoo(dot)fr> <cchristo_0899(at)yahoo(dot)fr>:
>
> Dear All,
>
> I have a java program that does bulk insertions (with transactions and
> PreparedStatements) in a postgresql database. I have a performance divided
> between two and four when using 9.3-1100 JDBC4 and 9.3-1101 in comparison
> with postgresql-8.4-703 JDBC4 independently of postgresql version.
>
> Time(ms) PG 8.4.7 9.3.4
> Driver
> 8.4-703 193390 188379
> 9.3.1101 349404 344344
>
> Does anybody else saw such a difference ? What reasons can explain it ?
>
> Another point, is that the bulk insertions are prerformed by parallel
> processes and 9.3-110x JDBC4 drivers appear to scale poorly.
>
> Thanks for any help.
>
> What to expect from "protocolVersoin=2"?
> Speed up or down?
>
> Edson
>
> --
>
> *Edson Carlos Ericksson Richter*
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