Oracle 11g for Windows is available for download

Dear all,

Most awaited Windows release of Oracle 11g is now available for download. You may download it from here: http://www.oracle.com/technology/software/products/database/index.html

Wishing you all a happy download!!

Regards

"1Z1-050: Oracle Database 11g New Features" Beta Exam declared

Oracle University has announced beta exam of "Oracle Database 11g New Features". As usual, the price of this beta exam is also $50.

Well, beta exams are really time consuming and this one is for more than 3 hours (190 minutes). So, get your coffee ready before proceeding to the exam.

More information can be obtained from the below URL:

http://education.oracle.com/pls/web_prod-plq-dad/db_pages.getpage?page_id=41&p_exam_id=1Z0_050

Note: 30 November, 2007 is the Exam Close date. Hurry ....

My best wishes for all beta exam takers !!!

Use of Oracle Sequences in PL/SQL Expressions

In this post, I will be discussing yet another new feature of Oracle database 11g. Well, this new feature is related to Oracle Sequences. With Oracle Database 11g, we can use SEQUENCE.NEXTVAL in PL/SQL expression instead of writing a SELECT statement. Here is an example:




Using SEQUENCE.NEXTVAL in PL/SQL assignment simply enhances readability, but, under the covers, Oracle rewrites the assignment into a SELECT statement. To verify the same, I traced a small PL/SQL block using 10046 trace as shown below:

Following is an extract from the trace file:

As you may see, Oracle has re-written the expression into equivalent SQL statement. Performance wise, this new feature does not give any benefit but the advantage we get is readability.

Thanks for reading :)

Read-Only Tables in Oracle 11g

In pre-Oracle 11g, one option to place a table in read-only mode is to create a trigger on that table that raises an exception on INSERT, UPDATE, and DELETE. In Oracle Database 11g, you can place a table in read-only mode by merely executing ALTER TABLE…READ ONLY statement.

Following is a simple test:

I create a test table “TEST1” and insert a dummy record. Using the ALTER TABLE …READ ONLY statement, I place “TEST1” table in read-only mode: Once a table is marked as read-only, all DML transactions are protected against that table. Any attempt to modify the “TEST1” table results in ORA-12081 error. You can find out whether a table is in read-only mode by querying “READ_ONLY” column of “USER_TABLES” view. A value of “YES” indicates that a table is read-only while a value of “NO” indicates a table is in read-write mode. At any time, you may place the table back in read-write mode using ALTER TABLE…READ WRITE statement. Read Oracle Database 11g Administrators Guide, for a complete list of allowed and barred operations on read-only tables.