Function result caching

Question

Hi All,
Using Oracle 10g Database, I would like to cache the return value of a pl/sql function. Also, whenever the underlying value changes, the cache entry has to be invalidated. Do we have any supported functionality by Oracle.
Regards

Answer 1

Hi,
Would it work for you to make the function DETERMINISTIC?
Table dropped.
SQL> set serveroutput on
SQL> create table t (x number)
Table created.
SQL> insert into t (x) values (1)
1 row created.
SQL> create or replace package stats
as
  cnt number;
end;
Package created.
SQL> create or replace function f
return number deterministic
is
  the_x number;
begin
  stats.cnt := stats.cnt + 1;
  select x into the_x from t;
  return the_x;
end;
Function created.
SQL> exec stats.cnt := 0
PL/SQL procedure successfully completed.
SQL> select count(f), max(f) from all_objects
  COUNT(F)     MAX(F)
     42705          1
1 row selected.
SQL> exec dbms_output.put_line(stats.cnt)
2
PL/SQL procedure successfully completed.
SQL> update t set x = 2
1 row updated.
SQL> commit
Commit complete.
SQL> exec stats.cnt := 0
PL/SQL procedure successfully completed.
SQL> select count(f), max(f) from all_objects
  COUNT(F)     MAX(F)
     42705          2
1 row selected.
SQL> exec dbms_output.put_line(stats.cnt)
2
PL/SQL procedure successfully completed.Regards
Peter