Evergreen now supports PostgreSQL 9.6 and 10. If you upgrade your database from a PostgreSQL version of 9.5, or lower, to PostgreSQL versions 9.6 or 10, you will need to recreate 3 indexes in additon to the normal database upgrade steps. The index recreation is necessary because of changes to the PostgreSQL unaccent extension module.

The following snippet of SQL code will do the necessary steps:

DROP INDEX actor_usr_first_given_name_unaccent_idx;
DROP INDEX actor_usr_second_given_name_unaccent_idx;
DROP INDEX actor_usr_family_name_unaccent_idx;
CREATE INDEX actor_usr_first_given_name_unaccent_idx ON actor.usr
      (evergreen.unaccent_and_squash(first_given_name));
CREATE INDEX actor_usr_second_given_name_unaccent_idx ON actor.usr
      (evergreen.unaccent_and_squash(second_given_name));
CREATE INDEX actor_usr_family_name_unaccent_idx ON actor.usr
      (evergreen.unaccent_and_squash(family_name));