CREATE TABLE local_posts
(
    id Int64,
    title String,
    description String,
    content String,
    user_id Int64,
    date Date
)
ENGINE = MergeTree()
PARTITION BY date
ORDER BY id;


INSERT INTO local_posts (id, title, description, content, user_id, date) VALUES(1, 'title', 'desc', 'content', 1, '2018-07-03')
INSERT INTO local_posts (id, title, description, content, user_id, date) VALUES(2, 'title', 'desc', 'content', 1, '2018-07-03')
INSERT INTO local_posts (id, title, description, content, user_id, date) VALUES(3, 'title', 'desc', 'content', 1, '2018-07-03')
INSERT INTO local_posts (id, title, description, content, user_id, date) VALUES(4, 'title', 'desc', 'content', 1, '2018-07-03')
INSERT INTO local_posts (id, title, description, content, user_id, date) VALUES(5, 'title', 'desc', 'content', 1, '2018-07-03')
INSERT INTO local_posts (id, title, description, content, user_id, date) VALUES(6, 'title', 'desc', 'content', 2, '2018-07-03')
INSERT INTO local_posts (id, title, description, content, user_id, date) VALUES(7, 'title', 'desc', 'content', 2, '2018-07-03')
INSERT INTO local_posts (id, title, description, content, user_id, date) VALUES(8, 'title', 'desc', 'content', 2, '2018-07-03')
INSERT INTO local_posts (id, title, description, content, user_id, date) VALUES(9, 'title', 'desc', 'content', 2, '2018-07-03')
INSERT INTO local_posts (id, title, description, content, user_id, date) VALUES(10, 'title', 'desc', 'content', 2, '2018-07-03')

select count(*) from local_posts

┌─count()─┐
│      10 │
└─────────┘



cat /var/lib/clickhouse/user_files/users.csv

1,test2@xample.com
2,test2@xample.com


sudo chown clickhouse:clickhouse /var/lib/clickhouse/user_files/users.csv


CREATE DICTIONARY local_users_dict
(
  user_id UInt64 DEFAULT 0,
  email String DEFAULT ''
)
PRIMARY KEY user_id
SOURCE(FILE(path '/var/lib/clickhouse/user_files/users.csv' format 'CSV'))
SETTINGS(format_csv_allow_single_quotes = 1)
LAYOUT(COMPLEX_KEY_HASHED)
LIFETIME(300)



select id, title, description, content, dictGetString('default.local_users_dict', 'email', (toUInt64(user_id), )), date AS user_email  from local_posts;

SELECT
    id,
    title,
    description,
    content,
    dictGetString('default.local_users_dict', 'email', tuple(toUInt64(user_id))),
    date AS user_email
FROM local_posts

Query id: 00a7b913-797d-49dc-9998-4cd8cc8209de

┌─id─┬─title─┬─description─┬─content─┬─dictGetString('default.local_users_dict', 'email', tuple(toUInt64(user_id)))─┬─user_email─┐
│  1 │ title │ desc        │ content │ test1@xample.com                                                             │ 2018-07-03 │
│  2 │ title │ desc        │ content │ test1@xample.com                                                             │ 2018-07-03 │
│  3 │ title │ desc        │ content │ test1@xample.com                                                             │ 2018-07-03 │
│  4 │ title │ desc        │ content │ test1@xample.com                                                             │ 2018-07-03 │
│  5 │ title │ desc        │ content │ test1@xample.com                                                             │ 2018-07-03 │
│  6 │ title │ desc        │ content │ test2@xample.com                                                             │ 2018-07-03 │
│  7 │ title │ desc        │ content │ test2@xample.com                                                             │ 2018-07-03 │
│  8 │ title │ desc        │ content │ test2@xample.com                                                             │ 2018-07-03 │
│  9 │ title │ desc        │ content │ test2@xample.com                                                             │ 2018-07-03 │
│ 10 │ title │ desc        │ content │ test2@xample.com                                                             │ 2018-07-03 │
└────┴───────┴─────────────┴─────────┴──────────────────────────────────────────────────────────────────────────────┴────────────┘

10 rows in set. Elapsed: 0.012 sec.