Month: January 2006

difference between EXPLAIN PLAN and SET AUTOTRACE TRACEONLY EXPLAIN

most of the time I use set autot trace exp in order to get the execution plan. It seems more easy than explain plan for [query]; followed by select * from table (dbms_xplan.display);. However, take care, set autotrace traceonly explain does modify the rows if you explain a plan for insert/update/delete. SQL> set autot trace […]

change MAXDATAFILES, MALOGFILES, MAXINSTANCES, MAXLOGMEMBERS without downtime

this is a 10gR2 new feature. It is no longer necessary to recreate the control file to increase those parameters. Actually, you do not have to change them, they change “automatically” Demo SQL> CREATE DATABASE MAXDATAFILES 5 MAXINSTANCES 1 MAXLOGFILES 2 MAXLOGMEMBERS 1 extent management local default tablespace users default temporary tablespace temp undo tablespace […]

select * from test where my_long like ‘%toto%’

A good way to learn is to try to answer user questions. Instead of referencing other posts, I tried today to answer that frequently asked question myself on developpez.com (french forum) SQL> create table test ( my_long long); Table created. SQL> insert into test values (‘hello toto !’); 1 row created. SQL> exec for r […]

oem grid control 10gR2 on Suse10

Last friday I installed RAC on my Suse10. Today, I installed Grid Control. Of course it is not supported. The packages I neeeded additionaly are db1 and openmotif. It did not work 100%. I finally started the iasconsole (emctl start iasconsole), and within the iasconsole, I restarted the failed elements. I created the repository manually […]