# URL(URL, Format) Manages data on a remote HTTP/HTTPS server. This engine is similar to the [`File`](./file.md#) engine. ## Using the engine in the ClickHouse server `The format` must be one that ClickHouse can use in `SELECT` queries and, if necessary, in `INSERTs`. For the full list of supported formats, see [Formats](../../interfaces/formats.md#formats). `The URL` must conform to the structure of a Uniform Resource Locator. The specified URL must point to a server that uses HTTP or HTTPS. This does not require any additional headers for getting a response from the server. `INSERT` and `SELECT` queries are transformed to `POST` and `GET` requests, respectively. For processing `POST` requests, the remote server must support [Chunked transfer encoding](https://en.wikipedia.org/wiki/Chunked_transfer_encoding). **Example:** **1.** Create a `url_engine_table` table on the server : ```sql CREATE TABLE url_engine_table (word String, value UInt64) ENGINE=URL('http://127.0.0.1:12345/', CSV) ``` **2.** Create a basic HTTP server using the standard Python 3 tools and start it: ```python3 from http.server import BaseHTTPRequestHandler, HTTPServer class CSVHTTPServer(BaseHTTPRequestHandler): def do_GET(self): self.send_response(200) self.send_header('Content-type', 'text/csv') self.end_headers() self.wfile.write(bytes('Hello,1\nWorld,2\n', "utf-8")) if __name__ == "__main__": server_address = ('127.0.0.1', 12345) HTTPServer(server_address, CSVHTTPServer).serve_forever() ``` ```bash python3 server.py ``` **3.** Request data: ```sql SELECT * FROM url_engine_table ``` ```text ┌─word──┬─value─┐ │ Hello │ 1 │ │ World │ 2 │ └───────┴───────┘ ``` ## Usage <<<<<<< HEAD - Multi-stream reading and writing are supported. ======= ## Details of Implementation - Reads and writes can be parallel >>>>>>> upstream/master - Not supported: - `ALTER` and `SELECT...SAMPLE` operations. - Indexes. - Replication.