| make_query_fast hint [message #652661] |
Wed, 15 June 2016 15:16  |
 |
Barbara Boehmer
Messages: 9101
Registered: November 2002
Location: California, USA
|
Senior Member |
|
|
This wasn't on our forums, but I just had to share. I am used to people comically suggesting the make_query_fast hint and such, but I don't think I have ever seen anybody not realize that it was a joke and actually test it and post the results.
https://community.oracle.com/thread/3940746
Then it continues to get better. No index. Still no query or explain plant posted. Waiting to see what happens next.
[Updated on: Wed, 15 June 2016 15:18] Report message to a moderator |
|
|
|
|
|
|
|
|
|
| Re: make_query_fast hint [message #652680 is a reply to message #652664] |
Thu, 16 June 2016 03:06  |
gazzag
Messages: 1119
Registered: November 2010
Location: Bedwas, UK
|
Senior Member |
|
|
It's an undocumented, secret parameter but just between friends:
SQL> ALTER SYSTEM SET _go_faster = 'YES' SCOPE = SPFILE;
SQL> SHUTDOWN IMMEDIATE;
SQL> STARTUP;
|
|
|
|
| Re: make_query_fast hint [message #652683 is a reply to message #652680] |
Thu, 16 June 2016 03:25 |
John Watson
Messages: 8962
Registered: January 2010
Location: Global Village
|
Senior Member |
|
|
|
You can also reduce the temperature in the data centre. As it drops towards 0K, the superconductivity effect raises the machine's clock speed.
|
|
|
|
|
|
| Re: make_query_fast hint [message #658621 is a reply to message #652757] |
Thu, 22 December 2016 00:32 |
rleishman
Messages: 3728
Registered: October 2005
Location: Melbourne, Australia
|
Senior Member |
|
|
Sorry to resurrect the dead, but this is my first visit back for a long time...
/*+ MAKE_QUERY_FAST */
You laugh, but in SQL Server, it exists (well, 'FAST' does). It's their version of the FIRST_ROWS hint. First time I saw it, I thought of this old Oracle meme.
Ross Leishman
|
|
|
|
| Re: make_query_fast hint [message #658974 is a reply to message #658621] |
Tue, 03 January 2017 02:51 |
Roachcoach
Messages: 1576
Registered: May 2010
Location: UK
|
Senior Member |
|
|
The other reason this sometimes works is when there's a series of legacy and now outdated hints in the code, someone slaps an invalid one at the start, takes out all the ones after it by accident and voilla, magically it is better because the old hints are now not applied.
SQL> explain plan for select /*+ full(t) */ count(*) from system.t t
2 /
Explained.
SQL> select * from table(dbms_xplan.display());
PLAN_TABLE_OUTPUT
--------------------------------------------------------------------------------
Plan hash value: 2966233522
-------------------------------------------------------------------
| Id | Operation | Name | Rows | Cost (%CPU)| Time |
-------------------------------------------------------------------
| 0 | SELECT STATEMENT | | 1 | 148 (0)| 00:00:01 |
| 1 | SORT AGGREGATE | | 1 | | |
| 2 | TABLE ACCESS FULL| T | 33984 | 148 (0)| 00:00:01 |
-------------------------------------------------------------------
9 rows selected.
SQL> explain plan for select /*+ GOD_PLEASE_GO_FASTER() full(t) */ count(*) from system.t t
2 /
Explained.
SQL> select * from table(dbms_xplan.display());
PLAN_TABLE_OUTPUT
--------------------------------------------------------------------------------
Plan hash value: 325870156
----------------------------------------------------------------------
| Id | Operation | Name | Rows | Cost (%CPU)| Time |
----------------------------------------------------------------------
| 0 | SELECT STATEMENT | | 1 | 22 (0)| 00:00:01 |
| 1 | SORT AGGREGATE | | 1 | | |
| 2 | INDEX FAST FULL SCAN| IDX1 | 33984 | 22 (0)| 00:00:01 |
----------------------------------------------------------------------
9 rows selected.
SQL>
[Updated on: Tue, 03 January 2017 02:56] Report message to a moderator |
|
|
|
) 1 Vote
] 
Blog
Search
Help
Members
Register
Login
Home
