Monday 8 November 2010

db link full spec

DROP DATABASE LINK "apollo";
CREATE DATABASE LINK "apollo"
connect TO xxxxxx
IDENTIFIED BY "xxxxxxx"
using '(DESCRIPTION =(ADDRESS_LIST =(ADDRESS=(PROTOCOL=tcp)(HOST=10.24.0.11)(PORT=1521)))(connect_data=(SID=MIS10G1)))';
SELECT * FROM dual@apollo

Thursday 28 October 2010

Wednesday 27 October 2010

direct connection

sqlplus user/pass@10.0.0.1:1521/service_name

Monday 25 October 2010

tnsping direct

the sytax

tnsping '(ADDRESS=(PROTOCOL=tcp)(HOST=10.24.0.11)(PORT=1521))'

Tuesday 19 October 2010

authid current_user

http://download.oracle.com/docs/cd/B19306_01/appdev.102/b14261/subprograms.htm#i18574

To give the package the same rights as the caller of the package.

Wednesday 2 June 2010

result cache

The two methods in 11g are

1) using a hint /*+ result_cache */
2) using the key words
result_cache
relies_on(table_name)

http://www.oracle.com/technology/oramag/oracle/07-sep/o57asktom.html

Wednesday 24 March 2010

INSERT /*+ APPEND */ a good idea ?

Sometimes , sometimes not
1) not good for many small inserts as it appends each insert above the high water mark, leaving lots of unused space
2) only one session at a time can do it at a time

see
http://asktom.oracle.com/pls/asktom/f?p=100:11:0::::P11_QUESTION_ID:1211797200346279484

Monday 8 March 2010

Oracle install on non Redhat Linux platform

./runInstaller -ignoreSysPrereqs


Specifically ODI

./runInstaller -ignoreSysPrereqs

Installs without a problem
except I had to chmod +x unzip

Post-install
JAVA_HOME=~/OraHome_1/jre/1.4.2
export JAVA_HOME

Then run
./operator.sh

Monday 18 January 2010

bitmap indexesneed frequent rebuilds

Do they or do they not deteriorate over time (i.e. after lots of inserts/updates) and need rebuilding?

Does this answer the question?
http://technology.amis.nl/blog/1420/myths-on-bitmap-indexes

The Jonathon Lewis' response #18 seems to suggest that it is only true after many 'updates' but not many inserts