How To Enable DDL Logging in the Database

If for whatever reason, you are required to log DDL, for example, I need to know why the LAST_DDL_TIME of a table was getting updated, you can do this from Oracle 11g.

To enable:

SQL> show parameter ENABLE_DDL_LOGGING

NAME TYPE VALUE
------------------------------------ ----------- ------------------------------ 
enable_ddl_logging boolean FALSE

SQL> ALTER SYSTEM SET ENABLE_DDL_LOGGING=TRUE;

System altered.

SQL> show parameter ENABLE_DDL_LOGGING

NAME TYPE VALUE
------------------------------------ ----------- ------------------------------ 
enable_ddl_logging boolean TRUE

To disable:

SQL> show parameter ENABLE_DDL_LOGGING

NAME TYPE VALUE
------------------------------------ -----------  (more...)

How to obtain the Historical Database Total Used and Allocated Size from OEM Repository

From time to time, it’s useful to know the total allocated size of a database at OS level, how much of it has been used and what the maximum total size the database can grow to at OS level, see blog post:
How to obtain the Database Total Used, Allocated and Max Size

However, it’s also goo to know the historical size.  The below query will give you this from the Oracle Enterprise Manager (OEM) repository:

 (more...)

How to obtain the Database Current, Total and Max Size

From time to time, it’s useful to know the total current size of a database at OS level, how much of it has been used and what the maximum total size the database can grow to at OS level.

The below query will give you this:

SELECT round(sum(used_ts_size)/1024/1024, 2) total_used_db_size_tb,
 round(sum(curr_ts_size)/1024/1024, 2) total_current_db_size_tb,
 round(sum(max_ts_size)/1024/1024, 2) total_max_allocated_db_size_tb
FROM
(SELECT df.tablespace_name, (df.bytes - sum(fs.bytes)) / (1024 * 1024) used_ts_size,
df.bytes / (1024 *  (more...)

Upgrade APEX 4 to 5.1.2

This blog post shows you how to upgrade APEX Version 4.0 on a default Oracle Database 11g XE instance to APEX 5.1.2. It divided into two parts. The first part confirms your starting point and the second installs and configures APEX 5.1.2. As a rule, you only should need to unlock the anonymous schema because these should be correctly set already.

Confirm Current Installation

  1. Verify the database version by connecting (more...)

Oracle SQL Strip Quotes

Somebody wanted to know how to strip double quotes from strings. Obviously, they’re playing with the DBMS_METADATA package. It’s quite simple, the TRIM function does it, like this:

SELECT TRIM(BOTH '"' FROM '"Hello World!"') AS "Message"
FROM   dual;

It will print:

Hello World!

As always, I hope this helps those looking for a solution.

RegExp: Constraint to prevent spaces at the beginning or end.

Even though a space is a regular character, the client didn't want spaces at the beginning or end of a string. Any spaces in the middle were fine.
Of course this could be handled by the application, but it must also be implemented in the database. Using a check constraint with a regular expression will prevent the end user from entering unwanted data.

To try things out, let's just start with a simple table with (more...)

Rounding amounts, divide cents over multiple lines

In previous articles I wrote about dealing with a missing cent when you need to divide a certain amount over multiple lines. In these articles, links are at the bottom, I described a method to calculate the difference on the last row.
Then a question arose (as a comment):
What if for example i have 42 records and i wish to divide 100 by 42. I would get a rounded value of 2.38. If (more...)

Rounding Amounts, the missing cent: with the MODEL clause

Rounding amounts may lead to rounding-issues, I have written how this may be resolved in a previous blogpost using some analytic functions.
Playing around a little bit, I also came up with a method to resolve the rounding difference with the MODEL clause.

To create an example, first let's create a table with only three records in it.


SQL> create table t
2 as
3 select rownum + 42 id
4 from dual
5 connect (more...)

Conditional Compilation and Static Boolean

One of my pet-projects is LoggerUtil, which is a utility for Logger, which is an excellent logging tool for PL/SQL.
This post is not about Logger, but some dealings with Conditional Compilation.

With Conditional Compilation you can create a single code base to handle different functionalities depending on compiler flags.
The latest addition to LoggerUtil was a method to create a custom template. For this to work, LoggerUtil depends on a certain Logger Release (where (more...)

Deadlock with a Virtual Column

Virtual Columns are really cool. I like them a lot. If you've never heard of them, shame on you, learn about them.
In short: a Virtual Column is not a real column, it's an expression that looks like a column... more or less.
While using the Virtual Columns, we ran into a little oddity with them.

First of all let's start with the version of the database that I tested this on. Yes, I know (more...)

Creating Database Using DBCA Silent Mode

Creating database using DBCA silent mode? Learn how to provision a database in a non-interactive mode.

The post Creating Database Using DBCA Silent Mode appeared first on VitalSoftTech.

Splitting a comma delimited string the RegExp way, Part Three

The article read most often on this blog is called "Splitting a Comma Delimited String, the RegExp way".
On this blog there are two articles about this technique, one is about splitting up a single string into multiple rows and the other is about multiple strings into multiple rows.
Links to both articles are included at the bottom of this article.
It seems like there is a need for functionality like that frequently. And just (more...)

Want to SPEED Up Your Database Tasks? DBMS_PARALLEL_EXECUTE to the rescue!

Use DBMS_PARALLEL_EXECUTE to divide one huge task into multiple small tasks that can be executed at the same time. See how many ways are there to divide.

The post Want to SPEED Up Your Database Tasks? DBMS_PARALLEL_EXECUTE to the rescue! appeared first on VitalSoftTech.

Configure Oracle Exadata Write Back Flash Cache

In addition to improving read I/Os, Oracle Exadata Write back flash cache also provides the ability to cache write I/Os directly to PCI flash. Exadata storage software version 11.2.3.2.1 is the minimum version required to use write back flash cache. Grid infrastructure and database homes must run 11.2.0.3.9 or later to use with Write-back Smart […]

The post Configure Oracle Exadata Write Back Flash Cache appeared first on VitalSoftTech.

Oracle Database 10g Certifications to Expire in March 01, 2015

Oracle Database is one of the leading relational database management system and is used all over the world. It has various training’s, exams and certifications for its Database and other products. However due to regular update in Database, they have to redesign their trainings, certification and exams to add new features and to remove old […]

The post Oracle Database 10g Certifications to Expire in March 01, 2015 appeared first on VitalSoftTech.

Free e-book giveaway: “Oracle Database XE 11gR2 Jump Start Guide” (Packt Publishing, 2012)

Last week I reviewed “Oracle Database XE 11gR2 Jump Start Guide” (Packt Publishing, 2012) in this post. Packt guys did like the review, and today I am pleased to announce that I will be giving away two free e-copies of the book. All you need to do is just comment below the post and win [...]

Book review: “Oracle Database XE 11gR2 Jump Start Guide” by Asif Momen

About a year ago Packt Publishing approached me and offered to write a book on (one of the technologies in) Oracle 11g. After careful consideration I had to decline the offer. Which was the right decision as I have hardly had any spare time in the past 12 months. However, Packt guys have kept in [...]

Who is using your Undo space? – Improved Script

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Hi folks!
I have extended the Undo usage scripts to include two additional indicators:
1) undo change vector size statistics
2) Used undo records/blocks

and support for RAC infrastructure, so you can spot the hungriest UNDO eaters for any given instance.

Then the script for Oracle 11g is as follows:
set pagesize 400
set linesize 140
col name for a25
col program for a50
col username for a12
col osuser for a12
SELECT a.inst_id, a.sid, c.username, c.osuser, c.program, b.name,
a.value, d.used_urec, d.used_ublk
FROM gv$sesstat a, v$statname  (more...)

Install Oracle Express XE 11gR2 on Oracle Linux 6.1 x64. (No bitmap index conversion on the fly!)

Some time ago, if you said you had installed Linux and, heavens forbid, Oracle on Linux, you’d be considered an utter geek. Fast forward 15 year. These days, when people (who have experience with other databases and operating systems) ask me about Oracle/Linux, I feel somewhat embarrassed. Let me illustrate what I mean. Install Oracle [...]

Tiny tips: Use Gateways to connect Oracle database to Microsoft SQL Server

When you have two Oracle databases and want to exchange data between them, it is easily done via database links. So for your local database you would go select * from local_table and for the remote one select * from remote_table@link_to_remote_db But what if the remote database isn’t Oracle, what if it’s (for example) Microsoft [...]