Author: Laurent Schneider

I just arrived at San Francisco and meet my colleague Daniel and Lutz Hartmann. Thanks Dani for driving us to SF and thanks Lutz for the Indian food in the restaurant where we ended last year during Blogger 2006 Meetup 🙂 . By the way do not miss 2007 Meetup organized by Mark Rittman : […]

I exported to CSV, formated and printed my schedule I will have to add the Unconferences too. Saturday I have a long long day to flight to San Francisco 😎

On Sunday you can assist to the 11g exam cram from 9am to 5pm. It may be too late to register, I tried anyway : 11g db Exam Cram Then you may want to get your OCP credentials for a discount price. on-site testing The Oracle Database 11g New Features for Administrators exam will be […]

Dear Friends, Planning to appear for Oracle DB 10g: Administration I exam, Would be very grateful if you send across braindumps/questions/tips related to that. Pl mail to this id : ***@yahoo.com Many Thanks, *** When I appeared to my first multiple choice question exam by Prometrics back in 1997, there were no brain dumps, no […]

I am in the processing in adding logfiles to a 10gR2 database. SQL> alter database add logfile group 10 size 1e7; Database altered. $ ls -l -rw-r—– 1 oracle 10000896 Nov 1 15:00 o1_mf_10_3lmq05ld_.log The file size is 10,000,896 bytes. What about this : SQL> alter database drop logfile group 10; Database altered. SQL> alter […]

I posted about Unexpected results in June 2005. Here are more results from NOT IN and NULL select * from dual WHERE (1) NOT IN (SELECT NULL FROM DUAL); no rows selected select * from dual WHERE (1,1) NOT IN (SELECT NULL,1 FROM DUAL); no rows selected However, and this surprised me, select * from […]

What is doing the MIN(DISTINCT X) call? Basically, every distinct value of X is passed to the MIN function. Well, it is probably of very little interest as the MIN function is very fast and processing less rows than MIN(X) should not boost the performance because of the overhead of sorting distinct values. However, if […]

10.2.0.4 should be available this year on Linux x86. Check Metalink Certification for different plateforms. Certify – Additional Info Oracle Database – Enterprise Edition Version 10gR2 On Linux (x86) Operating System: Linux (x86) Version SLES-10 Oracle Database – Enterprise Edition Version 10gR2 N/A Version N/A Status: Certified Product Version Note: None available for this product. […]

Yesterday I installed ContentDB. The installation is fairly straightforward. Download and install Oracle Identity Management OID 10.1.4.0.1 Install the Infrastructure, with the Identity Management and Repository, including Internet Directory, Single Sign-on, Delegated Administration Services and Directory provisioning This will create a 10.1.0.5 database. The default parameters are too low for contentDB. alter system set processes=250 […]

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I just read on Renaps Blog that Oracle 11g for Windows is out. Oracle Database Download

Oracle OpenWorld will host the On the wiki.oracle.com Wiki, you can create your own unconference session. I have proposed a session about SQL Model : SQL Model

Niall Litchfield just wrote about 11g availability on 64bits linux. Happy Birthday Niall Download Oracle Database

Oracle Support started a series about database internals. DATABASE INTERNALS NEWSLETTER Volume 1: October, 2007 Introduction to the Internals Newsletter Support Tips on Block Corruption What Constitutes a Severity 1 Issue? Note 460494.1

Nan select BINARY_DOUBLE_INFINITY INF, BINARY_DOUBLE_NAN NAN, greatest(BINARY_DOUBLE_INFINITY, BINARY_DOUBLE_NAN) GRE from t; INF NAN GRE — — — Inf Nan Nan Nan means not a number. It could be square root of -1, log of -1, 0/0, acos(1000), Inf-Inf, etc… select SQRT(-1d), LN(-1d), 0/0d, acos(1000d), BINARY_DOUBLE_INFINITY-BINARY_DOUBLE_INFINITY from t; SQR LN- 00D ACO BIN — — — […]

I have a table with a blob create table t(b blob); insert into t values (‘585858’); In 11g sql*plus, I can display raw data select b from t; B —— 585858 Ok, but if I want to display XXX (the character content) select utl_raw.cast_to_varchar2(b) from t; UTL — XXX However, in sql, a raw cannot […]

Addition is supposed to be associative. a+(b+c)=(a+b)+c This may be wrong in Oracle when dealing with months and days with t as (select interval ‘1’ month a, date ‘2007-09-26’ b, interval ‘7’ day c from dual) select a+(b+c),(a+b)+c from t; A+(B+C) (A+B)+C ———– ———– 03-NOV-2007 02-NOV-2007 The equality is supposed to be transitive if (a=b […]

I have start building my schedule. There are about 1722 sessions to chose from this year, so choice is difficult! Due to jet-lag, I mostly cannot do all what I planed. And I also like to spent some time by the exhibitors and the boosts. Ok, the one I will not miss : Steven Feuerstein […]

I have been to a SOUG last Thursday. We first had a presentation from Thomas Koch about performance in Zurich Kantonalbank. As I have been working as a DBA for about two years in that bank, I already had my opinion about performance there 😕 The second presentation was about TimesTen. I must say I […]

Today I opened two SR about flashback archive in 11g. In one of them, I complained that user SCOTT was not allowed to create a flashback archive. In the doc that I downloaded a few weeks ago I read : Prerequisites You must have the FLASHBACK ARCHIVE ADMINISTER system privilege to create a flashback data […]

I tried this in 11g TABLE T X 123 -1.2e-3 abc select x, to_number( xmlquery(‘number($X)’ passing x as x returning content)) n from t; X N ——- ———- 123 123 -1.2e-3 -.0012 abc it is quite a common task to extract numbers from varchar2 and to dig out poor quality data. select x, to_number(x) from […]

Download oracle-oid-10.1.4.2.0-1.0.i386.rpm Download oracle-xe-univ-10.2.0.1-1.0.i386.rpm Install the rpm # rpm -i oracle-*.i386.rpm In SLES 10, there is no /bin/cut, let’s create a link as root to avoid a mistake when running config-oid.sh # ln -s /usr/bin/cut /bin/cut Run the configure script as root # /etc/init.d/oracle-oid configure That’s all folks! It created an Oracle XE 10gR2 database, […]

I am always delighted to read the top features by Arup Nanda. He started his 11g series : Oracle Database 11g: The Top Features for DBAs and Developers There are many partitioning enhancements. The most exciting feature for me is the INTERVAL partitioning. A huge cause of downtime and waste of storage is the range […]

One of the problem with flashback queries in 10g and before is that you never know if it will works, especially you cannot expect to have flashback queries working for very old tables. Let’s imagine you want to export your CUSTOMER as of 30/6/2007. No chance in 10g… Well, with 11g, you can create a […]

What is wrong with this query? select*from”EMP”where’SCOTT’=”ENAME”and”DEPTNO”=20; EMPNO ENAME JOB MGR HIREDATE ———- ———- ——— ———- ——— 7788 SCOTT ANALYST 7566 13-JUL-87 It is a zero-space query 😎 You could write it as select * from “EMP” where ‘SCOTT’=”ENAME” and “DEPTNO”=20; personnaly, I would write it as select * from emp where ename=’SCOTT’ and deptno=20; […]

I have read a long long time ago the following note on positive infinity http://www.ixora.com.au/notes/infinity.htm Today I finally succeeded in inserting positive infinity in a number field create table t as select STATS_F_TEST(cust_gender, 1, ‘STATISTIC’,’F’) f from ( select ‘M’ cust_gender from dual union all select ‘M’ from dual union all select ‘F’ from dual […]

The use of a referential integrity constraint is to enforce that each child record has a parent. SQL> CREATE TABLE DEPT 2 (DEPTNO NUMBER PRIMARY KEY, 3 DNAME VARCHAR2(10)) ; Table created. SQL> CREATE TABLE EMP 2 (EMPNO NUMBER PRIMARY KEY, 3 ENAME VARCHAR2(10), 4 DEPTNO NUMBER 5 CONSTRAINT EMP_DEPT_FK 6 REFERENCES DEPT(deptno)); Table created. […]

This is a very neat feature in 11g. I have a script called foo.sql create table t(x number primary key); insert into t(x) values (1); insert into t(x) values (2); insert into t(x) values (2); insert into t(x) values (3); commit; It is eyes-popping that this script will return an error, but which one? Let’s […]

By reading Pete Finnigan’s Oracle security weblog today, I discovered that the password is no longer displayed in DBA_USERS in 11g. select username,password from dba_users where username=’SCOTT’; USERNAME PASSWORD ——– —————————— SCOTT select name,password from sys.user$ where name=’SCOTT’; NAME PASSWORD —– —————————— SCOTT F894844C34402B67 on the one hand, it is good for the security. On […]

as of today, 24-AUG-2007, here is the certification matrix for Linux x86 OS Product Status SLES-10 11g Certified Red Hat Enterprise AS/ES 5 11g Certified Red Hat Enterprise AS/ES 4 11g Certified Oracle Enterprise Linux 5 11g Certified Oracle Enterprise Linux 4 11g Certified

Shay Shmeltzer posted the link to the Oracle Openworld 2007 sessions : http://www.cplan.com/oracleopenworld2007/sanfrancisco/cc