OPEN_CONNECTION v14

The OPEN_CONNECTION function establishes a network connection to a specified host and port, returning a connection handle used for subsequent data transfer operations.

OPEN_CONNECTION (
  remote_host      IN VARCHAR2(255) DEFAULT NULL,
  remote_port      IN INTEGER,
  local_host       IN VARCHAR2(255) DEFAULT NULL,
  local_port       IN INTEGER      DEFAULT NULL,
  in_buffer_size   IN INTEGER      DEFAULT NULL,
  out_buffer_size  IN INTEGER      DEFAULT NULL,
  charset          IN VARCHAR2(30)  DEFAULT NULL,
  newline          IN VARCHAR2(2)   DEFAULT NULL,
  tx_timeout       IN INTEGER      DEFAULT NULL,
) RETURN connection;

Parameters

remote_host

The DNS name or IP address of the remote host to which you are connecting. If remote_host is NULL, the function uses the local host and port for the connection.

remote_port

The TCP port number of the remote host.

local_host

The local network interface address to bind to. If NULL, then system gives you an error.

local_port

The local TCP port number to bind to. If NULL, then system gives you an error.

in_buffer_size

The size (in bytes) of the input buffer used for receiving data.

out_buffer_size

The size (in bytes) of the output buffer used for sending data.

charset

The character set to be used for data transmission (e.g., 'UTF-8'). This parameter is accepted and not processed by the function.

newline

The newline character is appended to the text line sent by WRITE_LINE function.

tx_timeout

The timeout duration (in seconds) for transmission operations.

Return value

Notes

• Defaults: Most parameters are optional. At a minimum, remote_port must be specified if remote_host is handled by the underlying environment or defaults.

• Resource management: Every connection opened with this function should eventually be closed using the corresponding CLOSE_CONNECTION procedure to prevent resource leaks.

• Buffer tuning: For high-throughput applications, adjusting in_buffer_size and out_buffer_size can significantly impact performance based on the network MTU.

Example

DECLARE
  c      UTL_TCP.CONNECTION;
BEGIN   
  c := UTL_TCP.OPEN_CONNECTION('mail-arts.enterprisedb.com', 25);
  UTL_TCP.CLOSE_CONNECTION(c);
END;