Submitted by csm.dba on Tue, 2012-09-04 05:52
We all know that CHAR and VARCHAR2 are two different datatypes used for storing strings in Oracle. When I asked many people about what’s the difference exactly, all were saying VARCHAR2 can be used for variable sized character strings. As I’m not satesfied with the answer, as always, I’ve decided to do my own experiments on these two. Please find the exercise I’ve performed below.
SQL> create table t1 (col1 char(10), col2 varchar2(10));
SQL> insert into t1 values(‘Oracle’,'Oracle’);
1 row created.
Submitted by csm.dba on Tue, 2012-09-04 05:48
When I was doing a research on Oracle Database creation, through DBCA, last week, I came across a very interesting scenario which I couldn’t stop sharing with you :)
I have a cluster of machines (don’t confuse it with a RAC cluster but just a group of machines required for my application deployment) with 188.8.131.52 installed and a Database instance running.
I got a requirement to remove everything accumulated in the machine as a result of the Oracle installation and the Database creation: The installation directories, the datafiles, oratab entries etc…
Submitted by csm.dba on Tue, 2012-09-04 05:47
Hi Oracle geeks,
Last Friday, I’ve noticed a strange thing happening in my 184.108.40.206 Database: I’m able to create objects in a tablespace which is marked READ ONLY !!!
Don’t believe this?? See the below
SQL> create tablespace ro datafile ‘/xxx/RO.DBF’ size 10M AUTOEXTEND ON;
SQL> alter tablespace ro read only;
SQL> select status from dba_tablespaces where tablespace_name=’RO’;
SQL> sho user
USER is “CSM“
Submitted by manasn on Sun, 2012-08-12 17:58
I have just joined an in flight project and find the lead data modeler has created a name value pair data model.
The reason given was flexibility of data model considering some records can have as many as 900 attributes. The .Net application team seem to be loving it, as they can code everything with very few tables in mind.
I feel the model is difficult to query, difficult to load and difficult to syndicate and in all likelyhood will suffer from poor performance. Also the data model can't be considered as a rich metadata repository and difficult to understand.
Submitted by mbartov on Fri, 2012-08-10 11:07
I just posted a complete integrated set of tools to manage, monitor and tune the Oracle database.
It is free, no registration or email is required. I will just appreciate any kind of feedback to make it better.
The package comprises the following topics:
This section allows you to view and maintain virtually all database objects, including partitioned tables and materialized views. It also includes a function to view inter-dependency between objects.
Submitted by John Watson on Sun, 2012-08-05 01:31
Matthew Morris (who makes many constructive and knowledgeable contributions to the forum) has written a series of study guides for the OCA/OCP exams. I asked him if I could have a copy of one to review. The result: it's very good. This is a copy of the review I put up on Amazon.
Submitted by John Watson on Thu, 2012-07-12 06:38
The other day, I was asked how to move a table from one schema to another. The answer, as we all know, is "you can't do that: you have to create a new table as a copy of the old one, or use export/import. It will take a long long time." Not true.
Submitted by andy huang on Wed, 2012-06-06 09:05
OS:Red Hat Linux As 5
Submitted by mahir.quluzade on Tue, 2012-06-05 05:25
Submitted by John Watson on Tue, 2012-05-15 03:26