ClickHouse_URL_Engine.md

Events table (ordered by insertion):

CREATE TABLE events (
  id UInt64,
  ts DateTime64(3),
  data TEXT
)
ENGINE=MergeTree()
ORDER BY tuple()

Service table:

CREATE TABLE service1 (
  id UInt64,
  ts DateTime64(3),
  data TEXT
)
ENGINE=URL('https://service1.example.com/api/enrich', JSONEachRow)

Mat view:

CREATE MATERIALIZED VIEW events_enrich
TO service1 AS
SELECT
  id,
  ts,
  data
FROM events

What will happen:

• rows get inserted into events
• mat view will push them into the API endpoint (in JSONEachRow format) using POST HTTP request.
• rows will be batched: multiple rows per one POST.
• ClickHouse will not wait for any data in response, API should only answer with 200 ok and that's it.