SQL parsing efficiency

Is there any benefit (parsing, optimization, etc.) in writing PL/SQL conforming to modes 2 and 3 shown below?

Basically, is there a performance benefit to using variables or constants instead of hard-coded values?

1.
cursor csrTest is
select company_id
  from companies
 where type_code = 10; -- hard-coded value

2.
nTypeCode companies.type_code%type := 10;

cursor csrTest is
select company_id
  from companies
 where type_code = nTypeCode; -- variable value

3.
cnTypeCode constant companies.type_code%type := 10;

cursor csrTest is
select company_id
  from companies
 where type_code = cnTypeCode; -- constant value

Thanks,
Todd Received on Thu Jan 04 2001 - 19:19:38 CST