Trying to Understand Oracle Deterministic Function Speed Test Results - sql

Question

This question arose as a spin-off from this one: Adding Many (UDFs) Validation Functions to Oracle - Which Method Run Fastest
I am debating between putting a low level function that will be used everywhere in my application in an object as a CONSTRUCTOR FUNCTION so it's encapsulated with it's type that it returns, or just making the function STAND-ALONE. I know most would thing these test result are inconsequential because the loop count is so high. But in our app this function could be used to check multiple columns in each large loop iteration. So it really wouldn't be hard for us to reach 3 million checks in a single process. And this all reports back to a web page so the user is waiting on these results, so every msec matters.
So I was running some results and this is what I found...
/*****
isValid is a CONSTRUCTOR FUNCTION of an OBJECT
and it is deterministic
passing in:
'blah' -> 12 seconds
x -> 464 msecs
changing x to varchar2(7)
x -> 2 seconds (this is how we would use it in most cases within loops)
*****/
declare
x number;
--x varchar2(7);
begin
for i in 1 .. 3000000 loop
x := x + 1;
if (isValid(x,'number').result = 1) then
null;
end if;
end loop;
end;
/
/*****
isValid2 is a STAND-ALONE FUNCTION
and it is deterministic
passing in:
'blah' -> 407 msecs
x -> 4 seconds
changing x to varchar2(7)
x -> 4 seconds (this is how we would use it in most cases within loops)
*****/
declare
x number;
--x varchar2(7);
begin
for i in 1 .. 3000000 loop
x := x + 1;
if (isValid2(x,'number').result = 1) then
null;
end if;
end loop;
end;
/
Based on these result I think I'm going to go with the CONSTRUCTOR FUNCTION of an OBJECT approach.
So my question is: Why are the result between 'blah' and x completely reversed between the two different methods?
Oracle Database 11g Enterprise Edition Release 11.2.0.2.0 - 64bit Production
PL/SQL Release 11.2.0.2.0 - Production
CORE 11.2.0.2.0 Production
TNS for 64-bit Windows: Version 11.2.0.2.0 - Production
NLSRTL Version 11.2.0.2.0 - Production
PLSQL_OPTIMIZE_LEVEL = 2 (I've never read up on this, this is a test box, I'm not sure what it *should* be set to yet but I will read up on it)
PLSQL_CODE_TYPE = INTERPRETED (I know NATIVE is faster but they won't change it.)
Here is the stand-alone function...
create or replace type valObj as object (
result number(1),
resulttext varchar2(32000) );
/
create or replace function isValid2(v in varchar2, f in varchar2)
return valObj
deterministic
is
test PLS_INTEGER;
begin
if f = 'number' then
begin
test := to_number(v);
return valObj(1,null);
exception when VALUE_ERROR then return valObj(0,'Invalid number. Valid formats are: 12345, 12345.67, -12345, etc...');
end;
elsif f = 'phone' then
null; --TO DO
elsif f = 'integer' then
null; --TO DO
elsif f = 'email' then
null; --TO DO
elsif f = 'IPv4' then
null; --TO DO
elsif f = 'IPv6' then
null; --TO DO
end if;
--dozens of others to follow....
end;
/
And here is the object/function...
create or replace type isValid as object (
result number(1),
resulttext varchar2(32000),
constructor function isValid(v varchar, f varchar) return self as result deterministic );
/
create or replace type body isValid as
constructor function isValid(v varchar, f varchar) return self as result deterministic is
test PLS_INTEGER;
begin
if f = 'number' then
begin
test := to_number(v);
self.result := 1;
self.resulttext := null;
return;
exception when VALUE_ERROR then
self.result := 0;
self.resulttext := 'Invalid number. Valid formats are: 12345, 12345.67, -12345, etc...';
return;
end;
elsif f = 'phone' then
null; --TO DO
elsif f = 'integer' then
null; --TO DO
elsif f = 'email' then
null; --TO DO
elsif f = 'IPv4' then
null; --TO DO
elsif f = 'IPv6' then
null; --TO DO
end if;
--dozens of others to follow....
end;
end;
/