Store big JSON files into Oracle DB

Question

I\'m using the following script in order to read data from MongoDB as JSON files.

DECLARE
  l_param_list     VARCHAR2(512);
 
  l_http_request   UTL_HTTP.req;         


        

Answer 1

Your problem is in your call to UTL_HTTP.read_text. You are passing a CLOB, but read_text only accepts VARCHAR2, so it can return a maximum of 32k bytes.

You need to call it in a loop, using a VARCHAR2 buffer, and concatenate the results into your CLOB, e.g.:

DECLARE
  buf VARCHAR2(32767);
BEGIN
  LOOP
    UTL_HTTP.read_text(l_http_response, buf);
    l_response_text := l_response_text || buf;
  END LOOP;
EXCEPTION
  WHEN UTL_HTTP.end_of_body THEN
    NULL;
END;

http://docs.oracle.com/cd/E11882_01/appdev.112/e40758/u_http.htm#ARPLS71074

Your second problem is that json_ext.get_string only returns a VARCHAR2, which means it is limited to 32767 byes max. I've had a browse of the PL/json wiki, you might need to reach out to one of the authors to find out how to use it to get a CLOB value.