First letter alone in Upper case?

Question

Oracle 10G Enterprise edition
Hi all,
I am trying out to make the first letter alone in Upper case. The following query makes my output .
SELECT UPPER(SUBSTR('long string without upcase',1,1))||SUBSTR('long string without upcase',2) FROM DUAL
Long string without upcase
How can i replicate the same with Regular Expression? Which one is performance oriented?
The above one or the one with regular expression.
Help me out to get a clear idea.
Thanks
Ram

Answer 1

Even with very simple regular expressions substr performs a tick faster ( on 10.2.0.4)
SQL> select * from v$version where rownum < 2;
BANNER
Oracle Database 10g Enterprise Edition Release 10.2.0.4.0 - Prod
SQL> declare
  2  l_start number;
  3  l_initcap varchar2(100);
  4  begin
  5  l_start:=dbms_utility.get_time;
  6  for i in 1..100000 loop
  7  select upper(substr(ename,1,1))||substr(ename,2) into l_initcap from emp where rownum=1;
  8  end loop;
  9  dbms_output.put_line('SUBSTR Time: '||(dbms_utility.get_time - l_start));
10  l_start:=dbms_utility.get_time;
11  for i in 1..100000 loop
12  select initcap(REGEXP_SUBSTR(ename,'[^( )]+',1,1))||REGEXP_SUBSTR(ename,'[^( )]+',1,2)
13  into l_initcap
14  from emp
15  where rownum=1;
16  end loop;
17  dbms_output.put_line('REGEXP Time: '||(dbms_utility.get_time - l_start));
18  end;
19  /
SUBSTR Time: 314
REGEXP Time: 423
PL/SQL procedure successfully completed.I would however expect, with more complex regular expressions, the performance will decrease (but, of course, is only an assumption).
Best regards
Maxim