sqlite3 performance problems only in python
dstanek at dstanek.com
Thu Jul 23 18:09:55 CEST 2009
On Thu, Jul 23, 2009 at 9:02 AM, Stef Mientki<stef.mientki at gmail.com> wrote:
> btw, I don't know if it's of any importance, the SQL-statement I perform is
> select OPNAMEN.*, NAME, NAME_, SCORES.SCORE, PATIENT.*
> from OPNAMEN
> inner join POID_VLID on OPNAMEN.POID = POID_VLID.POID
> inner join VRAAGLST on VRAAGLST.VLID = POID_VLID.VLID
> inner join VLID_SSID on VRAAGLST.VLID = VLID_SSID.VLID
> inner join SUBSCHAAL_GEGEVENS on SUBSCHAAL_GEGEVENS.SSID = VLID_SSID.SSID
> inner join POID_SSID_SCID on ( OPNAMEN.POID =
> POID_SSID_SCID.POID ) and
> ( SUBSCHAAL_GEGEVENS.SSID =
> POID_SSID_SCID.SSID )
> inner join SCORES on SCORES.SCID =
> inner join PID_POID on OPNAMEN.POID = PID_POID.POID
> inner join PATIENT on PATIENT.PID = PID_POID.PID
> where substr ( lower( NAME) , 1, 6) = 'cis20r'
> and lower ( NAME_ ) = 'fatigue'
> and TEST_COUNT in (3,4)
> and DATETIME > 39814.0
> and SCORE < 30
Warning: I suck at SQL and hate it with a passion...
By using lower() on the left side of the where expressions I believe
that you are table scanning. So it is not the size of the data
returned, but the size of the data that needs to be scanned.
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