Dr. Tariff (
iOS,
Android) .
HDD . , . SSD . SSD ,
RAID-0 . PostgreSQL SSD .
1. PostgreSQL SSD RAID-0 SSD.
2. (SELECT UPDATE) , , .
. :
- SSD
- RAID-0 2- SSD
- SSD HDD
:
- Intel i7 4770.
- 16 Gb RAM.
- Intel SSD .
- Intel SSD 480 Gb 530 . Model – SSDSC2BW480A401
- Toshiba HDD 3000 Gb. Model – DT01ACA300
- – Ext4. SATA 3.
Linux Mint 17.2. PostgreSQL — «PostgreSQL 9.4.4 on x86_64-unknown-linux-gnu, compiled by gcc (Ubuntu/Linaro 4.6.3-1ubuntu5) 4.6.3, 64-bit»
SSD 440. SSD .

500 /, SATA .
Postgres :
shared_buffers = 2048 Mb
port = 5400
max_connections = 1000
3 :
- pg_bench
- Python Psycopg2
- Python SQLAlchemy
pgBench , . , . , , Python .
SQLAlchemy. SQL execute. , SQLAlchemy ( ) CPU.
Psycopg2 15%, , . Python c Psycopg2. Python .
:
CREATE TABLE numbers
(
"number" bigserial NOT NULL,
operator smallint,
region smallint,
CONSTRAINT numbers_pkey PRIMARY KEY (number)
)
:
'SELECT * FROM numbers WHERE number=%d'
.
:
'UPDATE numbers set region=%d, operator=%d WHERE number=%d'
. UPDATE , . INSERT DELETE . . , 1%.
RAID-0
mdadm. RAID , .
COPY. , . 1 1- .
SSD . – 1 . 42 21 . . , .

SELECT
. 16 , .

UPDATE
. 16 . – .
PostgreSQL
MVCC ACID. , 2 .
dead-, . , .

15-20%. . VACUUM. ,
.
PostgreSQL .

, . . . , - .
, SSD 1- .
, 980 . , , .
SSD RAID-0 10- .
, Dr. Tariff
Android iOS.
Facebook.