Hi,

this is my output:

1. ceilometer-dbsync: 
root@node-5:~# source openrc 
root@node-5:~# ceilometer-dbsync 
No handlers could be found for logger "oslo_config.cfg"


2. mongodb index list:

MongoDB shell version: 2.6.10
connecting to: test
ceilometer:PRIMARY> use ceilometer
switched to db ceilometer
ceilometer:PRIMARY> db.system.indexes.find()
{ "v" : 1, "key" : { "_id" : 1 }, "name" : "_id_", "ns" : "ceilometer.dummyData" }
{ "v" : 1, "key" : { "_id" : 1 }, "name" : "_id_", "ns" : "ceilometer.resource" }
{ "v" : 1, "key" : { "_id" : 1 }, "name" : "_id_", "ns" : "ceilometer.meter" }
{ "v" : 1, "key" : { "timestamp" : -1 }, "name" : "timestamp_idx", "ns" : "ceilometer.meter" }
{ "v" : 1, "key" : { "last_sample_timestamp" : -1 }, "name" : "last_sample_timestamp_idx", "ns" : "ceilometer.resource" }
{ "v" : 1, "key" : { "timestamp" : 1 }, "name" : "meter_ttl", "ns" : "ceilometer.meter", "expireAfterSeconds" : 604800 }
{ "v" : 1, "key" : { "last_sample_timestamp" : 1 }, "name" : "resource_ttl", "ns" : "ceilometer.resource", "expireAfterSeconds" : 604800 }
{ "v" : 1, "key" : { "_id" : 1 }, "name" : "_id_", "ns" : "ceilometer.event" }
{ "v" : 1, "key" : { "timestamp" : 1 }, "name" : "event_ttl", "ns" : "ceilometer.event", "expireAfterSeconds" : 604800 }
{ "v" : 1, "key" : { "_id" : 1 }, "name" : "_id_", "ns" : "ceilometer.alarm" }
{ "v" : 1, "key" : { "_id" : 1 }, "name" : "_id_", "ns" : "ceilometer.alarm_history" }
{ "v" : 1, "key" : { "timestamp" : 1 }, "name" : "alarm_history_ttl", "ns" : "ceilometer.alarm_history", "expireAfterSeconds" : 604800 }
{ "v" : 1, "key" : { "resource_id" : 1 }, "name" : "default_meter_resource_idx", "ns" : "ceilometer.meter" }
{ "v" : 1, "key" : { "user_id" : 1 }, "name" : "default_meter_user_idx", "ns" : "ceilometer.meter" }
{ "v" : 1, "key" : { "project_id" : 1 }, "name" : "default_meter_project_idx", "ns" : "ceilometer.meter" }
{ "v" : 1, "key" : { "counter_name" : 1 }, "name" : "default_meter_idx", "ns" : "ceilometer.meter" }
{ "v" : 1, "key" : { "user_id" : -1 }, "name" : "default_resource_user_idx", "ns" : "ceilometer.resource" }
{ "v" : 1, "key" : { "project_id" : -1 }, "name" : "default_resource_project_idx", "ns" : "ceilometer.resource" }
{ "v" : 1, "key" : { "event_type" : 1 }, "name" : "default_type_idx", "ns" : "ceilometer.event" }
ceilometer:PRIMARY> 


After applying this patch, I'm getting the same times:
time ceilometer statistics -q "timestamp>2016-07-01T00:00;timestamp<2016-08-01T00:00" -m memory.gb
+--------+---------------------+----------------------------+-----+-----+-----+--------+-------+------------+----------------------------+----------------------------+
| Period | Period Start        | Period End                 | Max | Min | Avg | Sum    | Count | Duration   | Duration Start             | Duration End               |
+--------+---------------------+----------------------------+-----+-----+-----+--------+-------+------------+----------------------------+----------------------------+
| 0      | 2016-07-01T00:00:00 | 2016-07-12T09:00:40.784000 | 8.0 | 1.0 | 2.6 | 4368.0 | 1680  | 601204.119 | 2016-07-05T10:00:36.665000 | 2016-07-12T09:00:40.784000 |
+--------+---------------------+----------------------------+-----+-----+-----+--------+-------+------------+----------------------------+----------------------------+

real	1m50.399s
user	0m0.957s
sys	0m0.053s