Обсуждение: AW: Strange query execution time

> Can  someone explain why the following query takes  1 second when using 
> LIKE and takes 30 seconds when replacing LIKE by = in the WHERE ? 

Because there is no optimization built in, that notices, that your
string does not contain a wildcard and would translate the restriction 
correspondingly. It is currently executed more or less like below:(I3.nameInfluence >= 'inf_vitesse' and
I3.nameInfluence< 'inf_vitessf'     and I3.nameInfluence LIKE  'inf_vitesse')
 
I already wanted to try to add this optimization myself, but lacked the time so far.
Anybody want to volunteer ?

TODO: add LIKE optimization to use = if constant does not contain any wildcards

Andreas

Zeugswetter Andreas SB <ZeugswetterA@wien.spardat.at> writes:
> TODO: add LIKE optimization to use = if constant does not contain any wildcards

Your information is obsolete ... try looking at the EXPLAIN VERBOSE
output for such a query.
        regards, tom lane