I am an Oracle DBA
daviewning has written 88 posts for DBTechZone

Oracle 11g R2 RMAN Clone

Duplicate a database using Rman backups in oracle 11gR2 RAC . Duplicating a database or database cloning creates a seperate database that contains all or subset of the source database. Here we don’t have to establish the network connection between the source and target host servers, we just need to copy all the rman backups … Continue reading

Perform data import on AWS RDS (Oracle) Modification will be re-posted shortly

Perform data import on AWS RDS (Oracle) Need modification will be re-posted shortly

Amazon Web Service – VPC, Subnet and CIDR

Amazon Web Service – VPC, Subnet and CIDR What is CIDR? CIDR-Classless Inter-Domain Routing. Classless Inter-Domain Routing is a method for creating additional addresses on the Internet. These addresses are provided to service providers (ISPs).And then assigned by the ISP to the customer. CIDR brings together the routes so that an IP address represents thousands … Continue reading

Disable root user remote access in Linux

Disable root remote login in Linux (SLES, CENTOS, Oracle Linux, Red Hat) It is the best practice to disable the root remote login in Linux. Login as a system user, then login as root if it is necessarily. To do this, using following Change the following to “no” Restart sshd

ORA-27054: NFS file system where the file is created or resides is not mounted with correct options

ORA-27054: NFS file system where the file is created or resides is not mounted with correct options This issue happened when I was trying to backup the archive log file on an Oracle RAC database Solutions The cause of the issue is because the NFS volume hasn’t been mounted correctly. umount the /backup01 on both … Continue reading

Oracle 11g R2 RAC on Oracle Enterprise Linux 5.11 with Virtual Box – Section 2 Install OEL 5.11

Install Oracle Enterprise Linux 5 upgrade 11 Insert the Oracle Enterprise Linux 5u11 iso into the virtual machine and powerup the virtual machine. Select the language English(English) and click Next Ignore the warning message by select Yes, click Next Select Create custom layout. and click Next Select the partition /dev/sda, Add Partition. Create a swap … Continue reading

ORA-01102 – cannot mount database in EXCLUSIVE mode

Set up an Oracle Database on ODA today for testing, but got an error as below Well, login to sqlplus to start it manually. Ennnnnn, back to node1 testodadb01, the instance 1 startup successfully After I read the trace file, I realized that the database is not in cluster mode: Okey Dokey, let’s fix it.

Oracle Streams – Section2

Oracle Streams – Section2 The basic capture process If the data is modified in the ORACLE database, it will be record into the redolog, so that when an error occurs, to have a way of correction. The Capture process as a background process oracle redolog has the ability to read, so it also has the … Continue reading

use ‘sed’ to list all content of a file after a specified word in Linux

In many cases, DBAs need to check the database log file. But if the database log contain million of rows how do we check the log by Date. Use ‘cat’ command will be very time consuming. Here is an example:

Oracle streams – Section1

Oracle Stream – Section1 Oracle Streams Overview Oracle Streams provides a way of sharing information, different from other data sharing mode, Streams even allows data transfer between different types of databases. Oracle Streams to achieve this by its replication process – capturing, transmission and applying. These three steps to transfer the specified information to the … Continue reading