This issue is created automatically through a Github pull request on behalf of PowerKiKi:
Support for Partial Indexes was available in Doctrine 1 following
http://www.doctrine-project.org/jira/browse/DC-82. This commit
reintroduce support for Doctrine 2. We use the same syntax with an
optionnal "where" attribute for Index and UniqueConstraint.
It is unit-tests covered and documented in manual.