qgis - How to optimize QgsFeatureRequest with filter expression

I have a point PostGIS layer (my_layer) which has more than 66000 features. I am getting the features I want but it takes too long. My code is:

    resultList = []
    req = QgsFeatureRequest().setFilterExpression(' "some_field_name" = \'some_value\' ')
    for feat in my_layer.getFeatures(req):

        name = feat.attribute("some_other_field")
        resultList.append(name)

How can I optimize it so that I can get the results quicker?

Answer

QGIS API provides you with a couple of ways for optimizing features requests.

In your case, if you don't need geometry and the rest of attributes in the result, you can:

• Use flag NoGeometry (see docs).


• Set subset of attributes you really need using setSubsetOfAttributes() (see docs).

That should speed your request up.