Description of problem:
'updatevdsdynamic' store procedure running too slow on scale setup, 
the function ration depends on the object(hosts, vms) capacity, while object capacity(sizing) growing up, it will hit the performance 
 
Version-Release number of selected component (if applicable):
3.4

How reproducible:
100%

Steps to Reproduce:
1.scale setup (530 hosts, ~4300 vms)

Actual results:
duration: 10919.393 ms execute <unnamed>: 
select * from updatevdsdynamic($1, $2, $3, $4, $5, $6, $7, $8, $9, $10, $11, $12, $13, $14, $15, $16, $17, $18, $19, $20, $21, $22, $23, $24, $25, $26, $27, $28, $29, $30, $31, $32, $33, $34, $35, $36, $37, $38, $39, $40, $41, $42, $43, $44, $45, $46, $47) as result

Expected results:
mo longer than 1 sec.

Additional info:
as required explain plan + analysis.

query for debug:

select * from updatevdsdynamic('4',
'4',
'Intel(Fake) CPU',
'1999.999',
NULL,
't',
'386',
'5831',
'3',
'1e8cd9a1-d6e3-4f08-b8b8-db13c1af5d00',
'1',
'1',
'1',
'0',
'321',
'65',
'vdsm-4.14.7-3.el6ev',
'4.14',
'Snow Man',
NULL,
'3',
'model_pentium3',
NULL,
'1',
'128',
'2',
'f',
'3.0,3.1,3.2,3.3,3.4',
'3.0,3.1,3.2,3.3,3.4',
'RHEL- 6Server- 6.5.0.0.el6',
'0.12.1.2-2.415.el6_5.9',
'libvirt-0.10.2-29.el6_5.7',
'0.12.4-6.el6',
NULL,
'2.6.32 - 431.20.3.el6.x86_64',
'iqn.1994-05.com.redhat:f086e0c266e',
'2',
'{before_vm_start={10_faqemu={md5=e3cb338	be6b9075a	04bed0e74	00ab7e2}},before_vdsm_start={fake_host.py={md5=72d9aae231d7b9f6eebb3387c31bbc99}},after_get_all_vm_stats={10_fakevmstats={md5=85aa50638834d47a9776997cbe69a760}}}',
'0',
'Red Hat',
'RHEV Hypervisor',
'6Server-6.5.0.1.el6',
'4C4C4544-0046-5710-8057-C8C04F365831',
'57c8cc45-ea8b-453c-9bd9-462f2	08b52d6',
'Red Hat Enterprise Linux',																																
NULL,
'rhel6.5.0') as result