All migrations fail when using Postgresql on Centos 6, with a "feature not supported" error on all database transactions when trying to migrate Drupal 7.43 to Drupal 8.1.2. (Both Drush and UI fail the same way.)
From error log:Migration failed with source plugin exception: SQLSTATE[0A000]: Feature not supported: 7 ERROR: cross-database references are not implemented: "d8.public.migrate_map_d7_url_alias" LINE 4: LEFT OUTER JOIN d8.public.migrate_map_d7_url_alias m... ^: SELECT ua.*, map.sourceid1 AS migrate_map_sourceid1, map.source_row_status AS migrate_map_source_row_status FROM @url_alias ua LEFT OUTER JOIN d8.public.migrate_map_d7_url_alias map ON pid = map.sourceid1 WHERE ( (map.sourceid1 IS NULL ) OR (map.source_row_status = :db_condition_placeholder_0) ); Array ( [:db_condition_placeholder_0] => 1 )
Centos 6.8, Postgres 9.5.3, php 5.6.22. Same error for all tables in the migration.