Please help us by providing the following info. Before posting please also check the pinned "Known issues" threads and make sure that you're running the latest available version for your oC release: https://owncloud.org/changelog/
Steps to reproduce
1. Log into owncloud
No duplicate key value violation errors should be logged into the pg_log file
Experiencing hundreds of insert statements into the oc_perferences object that continue to fail due to tuples already existing.
< 2016-08-16 04:57:05.279 CDT >STATEMENT: INSERT INTO "oc_preferences" ("userid", "appid", "configkey", "configvalue") VALUES($1, $2, $3, $4)
< 2016-08-16 04:57:05.388 CDT >ERROR: duplicate key value violates unique constraint "oc_preferences_pkey"
< 2016-08-16 04:57:05.388 CDT >DETAIL: Key (userid, appid, configkey)=(80fc9055-7cad-4d34-ad44-a0f19e3a4b8a, user_ldap, displayName) already exists.
Operating system: CentOS
Database: Postgresql 9.4
ownCloud version (see ownCloud admin page): 9.x
Updated from an older ownCloud or fresh install: Fresh installation using seeded data.
ownCloud log (data/owncloud.log, see https://central.owncloud.org/t/how-to-find-webserver-or-oc-logfile-enable-php-logfile/808):
Special configuration (external storage, external authentication, reverse proxy, server-side-encryption):
Integrity status for oC9+
Login as admin user into your ownCloud and access http://example.com/index.php/settings/integrity/failed paste the results here.