Database Oracle Security

Connection Encryption in Oracle Database

To encrypt connections between client and database server you have to set some parameters in sqlnet.ora file ($ORACLE_HOME/network/admin/sqlnet.ora) of server and client (you have to install oracle client on the client): server side: client side: the ENCRYPTION_CLIENT parameter can have one of these values: ACCEPTED : The client or server will allow both encrypted and […]

CentOS Linux Oracle Linux OS RedHat

How to setup a loadbalancer with HAProxy in RedHat 7

You have many options to install and configure a loadbalancer in RedHat 7. One of the best options is HAPorxy. To setup HAProxy, you have to download related RPM file and then install it: Then, you have to make changes in config file (/etc/haproxy/haproxy.conf): in this sample we have 4 servers as below: APP1: […]

CentOS Fedora Installation Linux Oracle Linux OS RedHat

Add New Disk to RedHat-based Linux without reboot

If you add a new disk to your OS, you won’t find this device in the device list (fdisk -l command). So you have two options to make it available: Reboot your machine Make the OS rescan all connected devices In operational environments, the first option is not considerable. So we have to choose the […]

Database MySQL

Change the Character Set & Collation of a table

To change the Character Set and Collation of a field of a table you have to use this query: if the table contains data, you have to update that data as follow:

Database Indexes Microsoft SQL Server

Rebuild and Reorganize all indexes within a database

If you want to REBUILD and REORGANIZE all your indexes in a database, you have to use this query: Rebuild: Reorganize:

Backup Restore Database Microsoft SQL Server

Backup/Restore Progress

To see the progress of Backup or Restore process you can use this query:

ASM Database Oracle

Database Startup Error: Fatal NI connect error 12547

If you see Fatal NI connect error 12547 error in alert log file of a Database in the middle of startup, and the database process couldn’t find DB PARAMETER FILE and CONTROL FILE, you have to check permissions,owner and group of these files: The permission of these files have to be 6751. The group of […]

Database Export/Import (EXPDP/IMPDP) Oracle

IMPDP Errors: ORA-02374, ORA-12899

If the Character set of source and destination database are not equal, you will see below errors in the impdp log file: to solve this error, you have to restore the structure of tables first then you have to modify these fields with alter table command as below: finally, we you have to import data […]

Database Installation Oracle

Grid Infrastructure & Oracle Database 12c – Preinstallation tasks

To install Oracle Grid Infrastructure & Oracle Database on Oracle Linux 7, you need to prepare your OS. To do so, you have to follow these commands: First of all, you have to install required packages in the OS: then, you have to edit /etc/hosts file and add the appropariate record as bellow: you may […]