UTL_HTTP call inside trigger leads to ORA-06502 when inserting from select

In order to allow a developer to make a SOAP call from an Oracle 11gR1 (11.1.0.7 PSU 24) instance using UTL_HTTP. He created a stored procedure : CREATE OR REPLACE PROCEDURE CALL_WS (URL IN VARCHAR2, REQUEST IN VARCHAR2, RESPONSE OUT VARCHAR2, ERRLOG OUT VARCHAR2) IS L_HTTP_REQ UTL_HTTP.REQ; L_HTTP_RESP UTL_HTTP.RESP; L_HTTP_URL_V VARCHAR2 (32767); IP_INPUTDATA_V VARCHAR2 (32767); L_OUTPUTDATA_V VARCHAR2 (32767); BEGIN L_HTTP_URL_V := URL; IP_INPUTDATA_V := REQUEST; ERRLOG := NULL; -- Configuration UTL_HTTP.SET_DETAILED_EXCP_SUPPORT (TRUE); L_HTTP_REQ := UTL_HTTP.BEGIN_REQUEST (L_HTTP_URL_V, 'POST', 'HTTP/1.1'); -- Authentification (not necessary at the moment) --UTL_HTTP.SET_AUTHENTICATION (L_HTTP_REQ, L_HTTP_USERNAME_V, L_HTTP_PASSWORD_V); UTL_HTTP.SET_PERSISTENT_CONN_SUPPORT (L_HTTP_REQ, FALSE); -- Headers UTL_HTTP.SET_HEADER (L_HTTP_REQ, 'Content-Type', 'text/xml'); UTL_HTTP.SET_HEADER (L_HTTP_REQ, 'charset', 'UTF-8'); UTL_HTTP.SET_HEADER (L_HTTP_REQ, 'Content-Length', LENGTH (IP_INPUTDATA_V)); --WRITES SOME TEXT DATA IN THE HTTP REQUEST BODY UTL_HTTP.WRITE_TEXT (L_HTTP_REQ, IP_INPUTDATA_V); -- GET HTTP RESPONSE L_HTTP_RESP := UTL_HTTP.GET_RESPONSE (L_HTTP_REQ); -- GET THE RESPONSE TEXT VALUE UTL_HTTP.READ_TEXT (L_HTTP_RESP, L_OUTPUTDATA_V); -- Check HTTP status code IF (L_HTTP_RESP.STATUS_CODE 200) THEN ERRLOG := 'HTTP REQUEST CALL FAILED. STATUS CODE IS ' || L_HTTP_RESP.STATUS_CODE; END IF; UTL_HTTP.END_RESPONSE (L_HTTP_RESP); -- Set Output parameter RESPONSE := L_OUTPUTDATA_V; EXCEPTION WHEN OTHERS THEN RESPONSE := NULL; ERRLOG := SQLERRM; END; And a BEFORE INSERT trigger as follows: CREATE OR REPLACE TRIGGER TR_kkk_AFTERIN BEFORE INSERT OR UPDATE ON CHU_kkk REFERENCING NEW AS N OLD AS O FOR EACH ROW DECLARE -- Variable declarations l_URL VARCHAR2 (32767); l_REQUEST VARCHAR2 (32767); l_RESPONSE VARCHAR2 (32767); l_ERRLOG VARCHAR2 (32767); v_def definitions.compterendu%TYPE; BEGIN IF :n.traite = 0 THEN -- Variable initializations l_URL := 'http://zz/uu/services.asmx '; v_def := NULL; -- Get request SOAP model in a Omnipro definition SELECT VALUE INTO v_def FROM definitions WHERE cle LIKE 'kkk'; IF v_def IS NOT NULL THEN -- Replace values in the request SOAP l_REQUEST := REPLACE(v_def, '@@DPTID@@', :n.dptid); l_REQUEST := REPLACE(l_REQUEST, '@@USERID@@', :n.userid); l_REQUEST := REPLACE(l_REQUEST, '@@APPTID@@', :n.apptid); l_REQUEST := REPLACE(l_REQUEST, '@@REFID@@', :n.refid); l_REQUEST := REPLACE(l_REQUEST, '@@REFAPP@@', :n.refapp); l_REQUEST := REPLACE(l_REQUEST, '@@DTEDEB@@', TO_CHAR(:n.dtedeb, 'yyyy-mm-dd')); l_REQUEST := REPLACE(l_REQUEST, '@@DTEFIN@@', TO_CHAR(:n.dtefin, 'yyyy-mm-dd')); l_REQUEST := REPLACE(l_REQUEST, '@@NUMNAT@@', :n.numnat); l_REQUEST := REPLACE(l_REQUEST, '@@NUMREF@@', :n.numref); -- Call CALL_WEB_SERVICE (URL => l_URL, REQUEST => l_REQUEST, RESPONSE => l_RESPONSE, ERRLOG => l_ERRLOG); IF l_ERRLOG IS NOT NULL THEN :n.traite := 9; :n.reflog := l_ERRLOG || ' : ' || SUBSTR (l_RESPONSE, 0, 1900); ELSE :n.traite := 1; END IF; :n.dtetrt := SYSDATE; END IF; END IF; EXCEPTION WHEN OTHERS THEN -- Consider logging the error and then re-raise :n.traite := 9; :n.reflog := SQLERRM; :n.dtetrt := SYSDATE; --RAISE; END; Everything works well for an INSERT query with a single value, but fails whenever he calls: INSERT INTO ... VALUES ... COMMIT; INSERT INTO ... VALUES ... COMMIT; He gets an ORA-06502. If he calls each insert separately, there is no error... I suggested him to investigate using SQLDeveloper debugger, but we are not sure that it will lead to something... What could cause that ?