Demo for Oracle Database Locking Policy

https://www.youtube.com/watch?v=6GUZ9STZ4po

Oracle Database Locking Policy – Back to Basics

Understanding how oracle internally manages the transactions is very crucial for your applications. Dealing with the database as a black box (sending queries and receiving results), will end up with bad performance to your application or/and non-scalable application. Oracle uses locks to internally manages the concurrent access to data.Only one transaction can modify any piece … Continue reading Oracle Database Locking Policy – Back to Basics

Oracle Virtual Machines for Sale !

Are you looking for a virtual machine to do some hands-on labs or practice something (i.e. for Educational purposes}? Do you have the time to build these virtual machines yourself? Below are some really nice Virtual Machines, that I invested allot of time to build on Oracle Virtual Box, and that I used them personally … Continue reading Oracle Virtual Machines for Sale !

Alter Pluggable Database Open – (ORA-00604/ORA-01405) After Apex Installation

While trying to open one pluggable database, I got the following errors: Background: While installing Apex 20.1 in one PDB, and while being very close to the installation completion, the session fully stucked.I restarted the database (the CDB), then I tried to open the PDB, but I got the above errors. While searching for this … Continue reading Alter Pluggable Database Open – (ORA-00604/ORA-01405) After Apex Installation

ORA-38760 While starting an Oracle Database

This is a quick post about an issue that I faced while trying to start one database yesterday. When I was trying to open one 12cR1 database, I got the following error: SYS SQL>alter database open;alter database open*ERROR at line 1:ORA-38760: This database instance failed to turn on flashback database The database status was "mounted": … Continue reading ORA-38760 While starting an Oracle Database

Is it possible to map one Tablespace to many Tablespaces with impdp?

I got this question from one of my clients. He is going to migrate one database from one platform to another. In this database many users are sharing the same tablespace. For example: In the current database, all application users are sharing the tablespaces “USERS” The client wants to change this, so as each schema … Continue reading Is it possible to map one Tablespace to many Tablespaces with impdp?

Oracle Database 20c is now Generally Available

Oracle Database 20c is now Generally Available on the cloud two days ago, 14-Feb-2020. Oracle 20c is next major database release. It includes many new fetaures espcially in the following areas: BlockchainMachine LearningSecurityJSONIn-Memory For a quick introduction to this new release:https://blogs.oracle.com/database/ga-of-oracle-database-20c-preview-release Also, for complete list of the new features, please refer to the:https://docs.oracle.com/en/database/oracle/oracle-database/20/newft/new-features.html Oracle Database … Continue reading Oracle Database 20c is now Generally Available

The Longest SQL Statement I have ever seen !

Below may be the longest SQL statement that I have ever seen. I don't know if it is written by one developer or group of developers and what is the logic behind it? I really don't like this style of writing sql statements. It is very difficult to be functionally understood. Also, it is very … Continue reading The Longest SQL Statement I have ever seen !

Oracle Database 19c (19.3) Installation on the Oracle Cloud Compute Instance.

As, I already have access to one Oracle Cloud Free Compute Instance (Oracle Linux), then I decided to install Oracle database 19c there and create a test database. This time, I'll use a different technique by installing Oracle Database rpm.Oracle delivered the oracle database software as rpm for Linux since Oracle 18c. Installation procedure is … Continue reading Oracle Database 19c (19.3) Installation on the Oracle Cloud Compute Instance.

Oracle Read Only Tables

Starting from Oracle 11gR1, oracle allows us to change a table to be a read-only table. Let us have a quick demo: I'm connecting as user HR ( to a 19c pluggable database). I have a small table "DEPT": So, now I'm going to change the table to be read only table: Now let us … Continue reading Oracle Read Only Tables