Database

Oracle LSNRCTL – Listener Shutdown and Startup Procedures

by Ramesh Natarajan on May 18, 2009

Oracle 11g lsnrctl Command Starting up and shutting down the oracle listener is a routine task for a database administrator. However a Linux system administrator or programmer may end-up doing some basic DBA operations on development database. It is critical for non-DBAs to understand the basic database admin activities.

In this article, let us review how to start, stop, check status of an oracle listener using Oracle listener control utility LSNRCTL.
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15 Practical PostgreSQL Database Administration Commands

by Ramesh Natarajan on April 16, 2009

PostgreSQL DBA Commands
Earlier we discussed about how to install PostgreSQL database on Linux from source.

In this article, let us review top 15 practical postgreSQL DBA command examples.

If you are a mySQL administrator, check-out our 15 examples of mysqladmin command article that we discussed a while back.

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9 Steps to Install and Configure PostgreSQL from Source on Linux

by Ramesh Natarajan on April 9, 2009

PostgreSQL Installation and Configuration Steps
Similar to mySQL, postgreSQL is very famous and feature packed free and open source database.

Earlier we’ve discussed several installations including LAMP stack installation, Apache2 installation from source, PHP5 installation from source and mySQL installation.

In this article, let us review how to install postgreSQL database on Linux from source code.

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Oracle Database Startup and Shutdown Procedure

by Ramesh Natarajan on January 26, 2009

Photo courtesy of Rob Shenk

For a DBA, starting up and shutting down of oracle database is a routine and basic operation. Sometimes Linux administrator or programmer may end-up doing some basic DBA operations on development database. So, it is important for non-DBAs to understand some basic database administration activities.

In this article, let us review how to start and stop an oracle database.

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How To Backup and Restore PostgreSQL Database Using pg_dump and psql

by Ramesh Natarajan on January 21, 2009

PostgreSQL DB Backup and Restore This is a guest post written by SathiyaMoorthy

pg_dump is an effective tool to backup postgres database. It creates a *.sql file with CREATE TABLE, ALTER TABLE, and COPY SQL statements of source database. To restore these dumps psql command is enough.

Using pg_dump, you can backup a local database and restore it on a remote database at the same time, using a single command. In this article, let us review several practical examples on how to use pg_dump to backup and restore.
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15 Practical Usages of Mysqladmin Command For Administering MySQL Server

by Ramesh Natarajan on January 14, 2009

In all the 15 mysqladmin command-line examples below, tmppassword is used as the MySQL root user password. Please change this to your MySQL root password.

1. How to change the MySQL root user password?

# mysqladmin -u root -ptmppassword password 'newpassword'

# mysql -u root -pnewpassword
Welcome to the MySQL monitor.  Commands end with ; or \g.
Your MySQL connection id is 8
Server version: 5.1.25-rc-community MySQL Community Server (GPL)

Type 'help;' or '\h' for help. Type '\c' to clear the buffer.

mysql>

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Overview of MySQL information_schema Database With Practical Examples

by Ramesh Natarajan on November 13, 2008

[MySQL Information Schema] Starting from MySQL 5, when you execute show databases command, information_schema will be listed in the database list. information_schema is a virtual MySQL database that stores metadata information of all the MySQL databases.

Typically you will execute either DESCRIBE or SHOW commands to get the metadata information. However using the information_schema views, you can execute the standard select SQL command to get the metadata information. In this article, let us review few practical examples on how to use the information_schema database.
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Increase Bugzilla Attachment Size Using MySQL max_allowed_packet

by Ramesh Natarajan on October 27, 2008

Bugzilla, an open source bug tracking system uses MySQL for the database. When you try to attach a document to the bug that is greater than 1MB in size, you will get the error message shown below. This article explains how to fix this problem by changing the MySQL max_allowed_packet database parameter and bugzilla maxattachmentsize parameter.

When a MySQL client or the mysqld server receives a packet bigger than max_allowed_packet bytes, it issues a Packet too large error and closes the connection.

MySQL client’s default max_allowed_packet value is 16MB. MySQL server’s default max_allowed_packet is 1MB. For bugzilla attachment, we need to increase the max_allowed_packet size of the MySQL server.
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