Comments on: New in Oracle 11g: PL/SQL Function Result Cache

By: Jurgen Kemmelings

Jurgen Kemmelings — Wed, 01 Aug 2007 09:34:30 +0000

Yes, it works exactly as you expect:

SQL> select test_result_cache(10) from dual;

TEST_RESULT_CACHE(10)
———————
10

Elapsed: 00:00:10.14
SQL> select test_result_cache(11) from dual;

TEST_RESULT_CACHE(11)
———————
11

Elapsed: 00:00:10.00
SQL> select test_result_cache(10) from dual;

TEST_RESULT_CACHE(10)
———————
10

Elapsed: 00:00:00.01
SQL> select test_result_cache(11) from dual;

TEST_RESULT_CACHE(11)
———————
11

Elapsed: 00:00:00.00
SQL>

By: Gareth Roberts

Gareth Roberts — Wed, 01 Aug 2007 06:15:51 +0000

Hi,
That looks like the deterministic option in prior versions, but with more functionality…
Cheers, Gareth

By: Steeve Bisson

Steeve Bisson — Tue, 31 Jul 2007 15:10:30 +0000

If you change the value p_in passed to the function test_result_cache( p_in in number ). Lets say 11.
Will it know not to use the cache in this case the first time 11 is passed to the function?

ex:

SQL> select test_result_cache(10) from dual;

TEST_RESULT_CACHE(10)
â€”â€”â€”â€”â€”â€”â€”
10

Elapsed: 00:00:10.35
SQL> select test_result_cache(11) from dual;

TEST_RESULT_CACHE(11)
â€”â€”â€”â€”â€”â€”â€”
11

Elapsed: 00:00:10.35
SQL> select test_result_cache(10) from dual;

TEST_RESULT_CACHE(10)
â€”â€”â€”â€”â€”â€”â€”
10

Elapsed: 00:00:00.00
SQL> select test_result_cache(11) from dual;

TEST_RESULT_CACHE(11)
â€”â€”â€”â€”â€”â€”â€”
11

Elapsed: 00:00:00.00

By: Jurgen Kemmelings

Jurgen Kemmelings — Tue, 31 Jul 2007 12:44:12 +0000

Many results can be cached. There is a database parameter RESULT_CACHE_MAX_SIZE that specifies the maximum amount of SGA memory that can be used for the result cache. Also there is a package DBMS_RESULT_CACHE to manage the cache, e.g. with DBMS_RESULT_CACHE.FLUSH you can flush the cache.
And yes, in the RELIES_ON() clause you can also mention a view if you do not have access to the table.

By: Patrick Wolf

Patrick Wolf — Tue, 31 Jul 2007 10:17:36 +0000

A really nice feature!

Do you know how many results are cached by Oracle? Is there a setting somewhere to define the size?
Another questions: With RELIES_ON, can I also reference a table where I don’t have direct read access, eg. in case if I just have access to the table through a view.

Thanks
Patrick