Bagaimana untuk melaksanakan prosedur tersimpan oracle

--procedure create_index
create or replace procedure create_index(indexName in varchar2, tableName in varchar2, columnName in varchar2)
i
tmp_name VARCHAR2(50);
TMP_SQL VARCHAR2(1024);
cnt NUMBER;
begin
select table_name into tmp_name from user_tables where upper(table_name)=upper(tableName);
if length(tmp_name)>0 then
SELECT COUNT(*) INTO cnt FROM USER_INDEXES T WHERE T.TABLE_NAME=''|| tableName ||'' AND T.INDEX_NAME=''|| indexName;
IF cnt = 0 THEN
execute immediate 'create index ' || indexName ||' on ' || tableName ||'('|| columnName ||') TABLESPACE TBS_TXNIDX';
END IF;
end if;
EXCEPTION
WHEN NO_DATA_FOUND THEN
BEGIN
NULL;
END;
end;

exec create_index('IDX_ORG_SET_PROCESS_1','CPS_ORG_SETTLEMENT_PROCESS','ORG_IDENTITY_ID ASC');

begin
create_index('IDX_STATEMENT_DETAIL_LINK','CPS_BANK_STATEMENT_DETAIL','LINK_TXN_ID ASC');
end;