Restarting MMON process

When I tried to do a simple change to a database parameter, I found an anormal or non-typical error, the ORA-00453 indicating that the MMON process was “dead”. Here is a small set of steps to restart it without problems for the database instance.

What happens if you delete the ORACLE_HOME?

Somebody asked me about what happens if the binary files stored in the ORACLE_HOME are deleted with the Database Instance up. Here I show you what happens when this deletion is made.

INSTR to search characters

The main goal of this post, is to know the different file systems where the Database’s data files are living on.

To do this, there must exist characters searches to manipulate and bring the first part of a file system.

Here I show how this can be easily done, indeed I have seen many people that have a little problems where they try to do some of this information segmentation.

How to delete a database

In this post, I take an interesting topic and nothing complicated of how to erase a single Oracle database. This affects only the database, nohing happens to the RDBMS binary files.

Synonyms management

In this ocassion, based on a search in my blog, I explain here in a simple and easy way the synonyms management in Oracle.

Automatic memory management

Starting with the Oracle database 11g version, there is an useful and Oracle recommended option to manage automatically the memory. When you modify some parameters of the instance, it can be implemented easily.

With this option, you just have to analyze the memory size that you want to establish and Oracle will administer its structures automatically. Its name is Automatic Memory Management (AMM).

Useful scripts for a DBA

After sometime, I was in a little debate between publish or not, my useful scripts that I personally use to query important information from the database and instance. Now I post these scripts and hope that will be useful for you too.

Bulk ASM disks’ creation with Linux

Maybe sometime, you’ll have the need to add a quantity of disks to the Automatic Storage Management (ASM) to be used in the disk groups and so, have enough space for the tablespaces’ data files. Here you’ll find how to do this in a  dynamic and fast way with the help of Linux tools.

Over which block device is mounted an ASM disk?

How to know over which block device is mounted a disk of the Oracle’s Automatic Storage Mangemente (ASM)?, it’s important to know this in order to determine which partition can be used for the creation of a new disk in that storage technology.

Big bdb files in a RAC

This post applies only for the 11.2.0.4 database version in RAC mode (Real Application Cluster), I don’t have any reference about this problem in other versions; if you have another version, you must test the solution before in an non-production environment and/or research in My Oracle Support.

The problem is that there are some files with bdb extension with a big size based on a bug of the database version, between these files, there is a special one called crfclust.bdb with a really big size.

Here you’ll find how to solve this little problem.