Today's musings

Today i read this article on performance tuning - basic thumb rules stuff which can be used as first tools:

http://www.softpanorama.org/DB/Oracle/oracle_performance_tuning.shtml


Always run explain plan from SQL plus

http://www.orafaq.com/forum/t/101980/2/

SQL> explain plan for select 'x' from dual;

Explained.

SQL> select * from table(dbms_xplan.display);

PLAN_TABLE_OUTPUT
--------------------------------------------------------------------------------
Plan hash value: 1388734953

-------------------------------------------------------------------------
| Id  | Operation        | Name | Rows  | Bytes | Cost (%CPU)| Time     |
-------------------------------------------------------------------------
|   0 | SELECT STATEMENT |      |     1 |       |     2   (0)| 00:00:01 |
|   1 |  FAST DUAL       |      |     1 |       |     2   (0)| 00:00:01 |
-------------------------------------------------------------------------

8 rows selected.

Also, use SET LINESIZE 120 to get a proper aligned explain plan that you can read.

What is my Oracle Block Size? 

http://stackoverflow.com/questions/4862724/query-my-block-size-oracle

Was required in reading up this article to determine if a particular table is good for including in a cluster. 

Determining candidates for cluster tables 

http://www.frontiernet.net/~rhode/cluster.html