Project: QGIS

Version: 2.10.0

Feature: PostGIS provider side expression filters

In QGIS 2.10 you can now filter features on the database server side. Only supported expressions will be sent to the database. Expressions using unsupported operators or functions will gracefully fallback to local evaluation.

To make use of this feature you need to enable it in Settings -> Options -> data sources. If your filter expression is PostgreSQL compliant it will automatically be run on the server side. You can also make use of this feature when using the python API for example when using these calls.

QgsFeatureRequest().setFilterExpression( expression )

or

QgsVectorLayer::getFeatures( expression )