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Showing posts from May, 2018

Setting up Network on Database server using the Command Line

Sometimes as a DBA you may find yourself in a database server environment without any graphical interface and you are forced to use the command line to setup the network. The procedure below shows you how to do that:- You setup a dynamic IP by editing the file: /etc/sysconfig/network-scripts/ifcfg-eth0 as root user It should look like this: DEVICE=eth0 HWADDR=08:00:27:37:A4:23 -------- ( ! replace with your network device macc addr ) TYPE=Ethernet UUID=6c8852cb-7819-46a3-9d ------- ( ! must not be the same) ONBOOT=yes --- ( ! very important) NM_CONTROLLED=yes BOOTPROTO=dhcp For static ip edit the same file if you are using the device eth0 and just add the following: DEVICE=eth0 BOOTPROTO=STATIC IPADDR=192.168.0.5 NETMASK=255.255.255.0 GATEWAY=192.168.0.1 ONBOOT=yes After saving the changes, you need to restart the network daemon using the following command:- $ sudo /etc/init.d/network stop $ sudo /etc/init.d/network start This should provide IP address...

AUTOMATING STARTING AND STOPPING THE DATABASE AND LISTENER ON LINUX

It is sometime desirable by most DBAs to have the oracle database and listener automatically shutdown and startup when the server reboots. The following steps shows you how to automate your database and listener shutdown and startup. Please note that this demonstration is linux centric (I am working on OEL 6.8), so if you are working with a different Unix platform, refer to the Oracle Database Admin’s Guide. 1. Edit the /etc/oratab file, and place a Y at the end of the entry for the database you want to restart automatically when the system reboots. You will need root priv to edit the file: 2. Paste within the file a line similar to the one below, for your environment: db11g:/u01/app/oracle/product/11.2.0/dbhome_1:Y Note: The entries are of the form: #   $ORACLE_SID:$ORACLE_HOME:N|Y: 3. As root, navigate to the /etc/init.d directory, and create a file named dbora: Paste the following lines in the dbora file. Make sure you...

Aspects of Implementing and Maintaining Indexes

There are various aspects of implementing and maintaining indexes. The table below summarizes some to the guidelines and techniques for creating indexes. Guideline Reasoning Create as many indexes as you need, but try to keep the number to a minimum. Add indexes judiciously. Test first to determine quantifiable performance gains. Indexes increase performance, but also consume disk space and processing resources. Don’t add indexes unnecessarily. The required performance of queries you execute against a table should form the basis of your indexing strategy. Indexing columns used in SQL queries will help performance the most. Consider using the SQL Tuning Advisor or the SQL Access Advisor for indexing recommendations. These tools provide recommendations and a second set of "eyes" on your indexing decisions. Create primary key constraints for all tables. This will automatically create a B-tree index (if the colu...