Posts

Showing posts from December, 2011

MYSQL,Postgres

Q.What's MySQL ? Ans: MySQL (pronounced "my ess cue el") is an open source relational database management system (RDBMS) that uses Structured Query Language (SQL), the most popular language for adding, accessing, and processing data in a database. Because it is open source, anyone can download MySQL and tailor it to their needs in accordance with the general public license. MySQL is noted mainly for its speed, reliability, and flexibility. ... Q. What is DDL, DML and DCL ? Ans: If you look at the large variety of SQL commands, they can be divided into three large subgroups. Data Definition Language deals with database schemas and descriptions of how the data should reside in the database, therefore language statements like CREATE TABLE or ALTER TABLE belong to DDL. DML deals with data manipulation, and therefore includes most common SQL statements such SELECT, INSERT, etc. Data Control Language includes commands such as GRANT, and mostly concerns with ri

SAN and NAS Interview questions

What is a SAN? SAN is short for Storage Area Network. It is a high-speed network of storage elements, similar in form and function to a LAN that establishes direct and indirect connections between multiple servers and multiple storage elements. The SAN is an extension of the server’s storage bus https://devops-geek.blogspot.com/2011/12/san-and-nas-interview-questions.html What does a SAN do? SANs create connectivity. SANs offer a method of attaching storage that improves data reliability, availability and performance SAN overcomes traditional network bottlenecks by connecting in three ways: Server-to-storage (direct attached storage) Server-to-server (network attached storage) Storage-to-storage (SAN Attached Storage) Name some of the SAN topologies and Explain each of them ? Point-to-point, arbitrated loop, and switched fabric topologies Point-to-Point  A point-to-point connection is the simplest topology. It is used when there are exactly two nodes and future