> 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