These are from zabbix_server.log on restart.

30302:20150120:083102.798 query [txnlev:0] [select alert_history,event_history,refresh_unsupported,discovery_groupid,snmptrap_logging,severity_name_0,severity_name_1,severity_name_2,severity_name_3,severity_name_4,severity_name_5 from config where 1=1 and configid between 0 and 99999999999999]
30302:20150120:083102.798 query [txnlev:0] [select i.itemid,i.hostid,h.proxy_hostid,i.type,i.data_type,i.value_type,i.key_,i.snmp_community,i.snmp_oid,i.port,i.snmpv3_securityname,i.snmpv3_securitylevel,i.snmpv3_authpassphrase,i.snmpv3_privpassphrase,i.ipmi_sensor,i.delay,i.delay_flex,i.trapper_hosts,i.logtimefmt,i.params,i.status,i.authtype,i.username,i.password,i.publickey,i.privatekey,i.flags,i.interfaceid,i.lastclock from items i,hosts h where i.hostid=h.hostid and h.status in (0) and i.status in (0,3) and i.itemid between 0 and 99999999999999]
30302:20150120:083114.923 query [txnlev:0] [select distinct t.triggerid,t.description,t.expression,t.error,t.priority,t.type,t.value,t.value_flags from hosts h,items i,functions f,triggers t where h.hostid=i.hostid and i.itemid=f.itemid and f.triggerid=t.triggerid and h.status in (0) and i.status in (0,3) and t.status in (0) and t.flags not in (2) and h.hostid between 0 and 99999999999999]

Zabbix server runs some queries each time it restarts. And it takes very long for this query to execute.
30302:20150120:083114.923 query [txnlev:0] [select distinct t.triggerid,t.description,t.expression,t.error,t.priority,t.type,t.value,t.value_flags from hosts h,items i,functions f,triggers t where h.hostid=i.hostid and i.itemid=f.itemid and f.triggerid=t.triggerid and h.status in (0) and i.status in (0,3) and t.status in (0) and t.flags not in (2) and h.hostid between 0 and 99999999999999]