[PyQt] QSqlDatabase connection parameters

[Scott Frankel]

Hi all,

Would anyone have any suggestions for improving QSqlDatabase PSQL  
connection performance?


The Qt docs refer to PSQL connection options and demonstrate the  
"requiressl=1" example.  Are there other options that can be set?   
(eg:  the docs' PostgreSQL "options" bullet point)  Google searches  
are coming up short.

I note that my local postgresql.conf file has a "work_mem" statement.   
(Usage:  work_mem = 1MB)  That could be germane, but including the  
term in my setConnectOptions() method (as part of a semi-colon  
separated list) yields PSQL errors.

I've optimized my working code further.  Running from a local data  
set, launch times are down to 4 seconds.  Running from an identical  
data set hosted remotely, my application launches in 40+ seconds!

Thanks in advance!
Scott



On Mar 16, 2010, at 9:09 PM, Scott Frankel wrote:

>
> Hi all,
>
> Is there a buffer size or similar optimization parameter that can be  
> set for QSqlDatabase PSQL connections?  The docs refer to PostgreSQL  
> "options" without specifying what they may be.
>
> I have a PG database cluster of about 7MB, spread over a couple  
> dozen tables.  Locally, it takes about 6 seconds to launch my app,  
> loading the model data into my forms.
>
> When I pull an identical data-set from a remote location, my  
> application launch time increases to over 60 seconds.  Yet resource  
> utilization on the remote server is miniscule.
>
> For comparison, I'm able to download the results of a 21MB SELECT  
> statement in less than 8 seconds via cmd-line psql.  That's orders  
> of magnitude more data in an order of magnitude less time!
>
> I'm creating my db connection as follows.  (Sample code attached  
> also.)
>
> 	db = QtSql.QSqlDatabase.addDatabase("QPSQL")
> 	db.setDatabaseName("fubar")
> 	db.setHostName("localhost")
> 	db.setUserName("admin")
> 	db.setPassword("abc123")
>
>
> Thanks in advance!
> Scott
>
>
> <dbTest.002.py>
>
>
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