Steps to reproduce:

1. Create a user of type "Zabbix Admin" or "Zabbix User"
2. Assign user to user group with read-write permissions on a number of hosts, or all hosts, and the ability to edit some or all templates. The number does not seem to matter; I've tried several different permutations to see if I can isolate the issue, but altering the permissions of the user's user group does not make a difference.
3. Attempt to load a page like the Monitoring -> Latest Data, Monitoring -> Hosts, Configuration -> Hosts, Configuration -> Templates etc. and it takes between twelve to eighteen seconds for the page to load, if it loads at all. Frequently we were getting a Gateway Timeout response until I upped the timeout limit. I have monitored the Zabbix server logs during this and I do not see any notifications of slow queries or errors. postgresql.conf and zabbix_server.conf files are attached.

Result:
See screenshot...
See log file...
See memory dump...
Expected:
See screenshot....
See attached patch file...