555*DBMS_PIPE.RECEIVE_MESSAGE(CHR(99)||CHR(99)||CHR(99),15)

Here's what that call means in Oracle DBMS_PIPE context:

• CHR(99)||CHR(99)||CHR(99) builds the string 'ccc'. This is the pipe name.
• DBMS_PIPE.RECEIVE_MESSAGE(p_pipe_name, p_timeout) tries to receive the next message from the pipe named 'ccc'.
• p_timeout = 15 means wait up to 15 seconds for a message.

What happens:

• If a message is available in pipe 'ccc' within 15 seconds, it returns that message as a VARCHAR2 and the message is removed from the pipe.
• If no message is available within 15 seconds, it returns NULL.
• The call can raise exceptions if the pipe doesn't exist or you lack privileges, etc.

Example:

• If some process did DBMS_PIPE.SEND_MESSAGE('ccc', 'HELLO'), then DBMS_PIPE.RECEIVE_MESSAGE(CHR(99)||CHR(99)||CHR(99),15) would return 'HELLO' (and delete it from the pipe).

Notes:

• The preface 555* is not Oracle syntax; it might be a question numbering or annotation.
• Use EXECUTE or PL/SQL block to capture the return value, e.g., v_msg := DBMS_PIPE.RECEIVE_MESSAGE('ccc', 15);.