Steps to reproduce the issue

Setting up new multi-language site (5 languages), with PostGresQL 8.4.10.

Expected result

Joomla multi-language site.

Actual result

Joomla multi-language site with post-install errors that cannot be fixed.

Error

ERROR: column "a.title" must appear in the GROUP BY clause or be used in an aggregate function LINE 1: SELECT a.id, a.title, a.checked_out, a.checked_out_time, a.... ^SQL=SELECT a.id, a.title, a.checked_out, a.checked_out_time, a.created, a.hits,l.title AS language_title, l.image AS language_image,uc.name AS editor,ag.title AS access_level,c.title AS category_title,ua.name AS author_name,COUNT(asso2.id)>1 as association FROM #__content AS a LEFT JOIN "#__languages" AS l ON l.lang_code = a.language LEFT JOIN #__users AS uc ON uc.id=a.checked_out LEFT JOIN #__viewlevels AS ag ON ag.id = a.access LEFT JOIN #__categories AS c ON c.id = a.catid LEFT JOIN #__users AS ua ON ua.id = a.created_by LEFT JOIN #__associations AS asso ON asso.id = a.id AND asso.context='com_content.item' LEFT JOIN #__associations AS asso2 ON asso2.key = asso.key GROUP BY a.id, l.title, l.image, uc.name, ag.title, c.title, ua.name ORDER BY a.hits DESC LIMIT 5
ERROR: column "a.title" must appear in the GROUP BY clause or be used in an aggregate function LINE 1: SELECT a.id, a.title, a.checked_out, a.checked_out_time, a.... ^SQL=SELECT a.id, a.title, a.checked_out, a.checked_out_time, a.access, a.created, a.created_by, a.created_by_alias, a.featured, a.state,l.title AS language_title, l.image AS language_image,uc.name AS editor,ag.title AS access_level,c.title AS category_title,ua.name AS author_name,COUNT(asso2.id)>1 as association FROM #__content AS a LEFT JOIN "#__languages" AS l ON l.lang_code = a.language LEFT JOIN #__users AS uc ON uc.id=a.checked_out LEFT JOIN #__viewlevels AS ag ON ag.id = a.access LEFT JOIN #__categories AS c ON c.id = a.catid LEFT JOIN #__users AS ua ON ua.id = a.created_by LEFT JOIN #__associations AS asso ON asso.id = a.id AND asso.context='com_content.item' LEFT JOIN #__associations AS asso2 ON asso2.key = asso.key GROUP BY a.id, l.title, l.image, uc.name, ag.title, c.title, ua.name ORDER BY created DESC LIMIT 5
An error has occurred.

System information (as much as possible)

PHP 5.6, PostGreSQL 8.4.10

Additional comments

However on another system with PHP 5.6 and PostGreSQL 9.3 this issue cannot be reproduced. So it appears to be an issue of a rather old PostgreSQL version (2011-12-05).