Re: performance issue with psycopg

On Mon, 2011-12-12 at 17:20 +0000, Daniele Varrazzo wrote:
> On Mon, Dec 12, 2011 at 4:41 PM, Sushant Sinha <sushant354@gmail.com> wrote:
> > I am using psycopg 2.4.2 and facing performance issue. An explain
> > analyze of the query on the database shows 0.75secs. But when used
> > through the psycopg layer I am seeing 1.5 secs. Any idea why the extra
> > cost and how to optimize it?
> >
> > from psycopg2.extras import DictCursor
> > from psycopg2.extensions import UNICODE, UNICODEARRAY
> > psycopg2.extensions.register_type(UNICODE)
> > psycopg2.extensions.register_type(UNICODEARRAY)
> >
> >
> > cursor = dbCnx.cursor(cursor_factory=DictCursor)
> > cursor.execute(query, params)
> > results = cursor.fetchall()
>
> What is the performance using only the basic cursor? And how big is
> the returned set?
>
> -- Daniele


Number of rows: 25111, number of columns: 12
With basic cursor it is 1.2 secs

        1    0.000    0.000    1.230    1.230 a.py:1(<module>)
        1    0.876    0.876    0.877    0.877 {method 'execute' of
'psycopg2._psycopg.cursor' objects}
        1    0.142    0.142    0.202    0.202 {method 'fetchall' of
'psycopg2._psycopg.cursor' objects}
        1    0.000    0.000    0.148    0.148 db_utility.py:1(<module>)
        1    0.002    0.002    0.132    0.132 extras.py:5(<module>)
        1    0.000    0.000    0.125    0.125 uuid.py:45(<module>)
        2    0.000    0.000    0.120    0.060 util.py:235(find_library)
        2    0.000    0.000    0.120    0.060
util.py:207(_findSoname_ldconfig)