Database Design & Optimization

One of the main functions of a DBA is to maintain database indexes. There have been several tips written about different commands to use for both index rebuilds and index defrags as well as the differences between index maintenance with SQL Server. In addition, other tips have been written about using maintenance plans to maintain indexes on all databases. One of the issues with maintenance plans is that they don't always seem to be as reliable as you would hope

Generally the indexing is done automatically in MS SQL database. If you need to reindex the database for any reason, you can use the tips here. First of all backup the databse before starting the reindexing. So anything goes wrong, you can get your DB back.

The reason I started to use this script to find out longest running query as if query is changed a bit it will display it as new row and new log start time. This way when I am improving T-SQL query or Stored Procedure I can check their progress in the query and does not have to get bothered with previous data.

Security is a major concern for the modern age systems/network/database administrators. It is natural for an administrator to worry about hackers and external attacks while implementing security. But there is more to it. It is essential to first implement security within the organization, to make sure right people have access to the right data.

There are so many variants of SQL that it is hard sometimes to figure out what to use. Here is a short article that briefly explains the difference between SQL and PL/SQL. Enjoy!

Triggers are stored procedures which are fired when data is modified in an underlying table. They can evaluate data being added to a table for validation purposes, or can make changes in that or other fields depending on the value of that data. You can use them even to execute a separate stored procedure, or to roll back a data modification or an entire transaction.

A denial-of-service attack (DoS attack) or distributed denial-of-service attack (DDoS attack) is an attempt to make a computer resource unavailable to its intended users. Although the means to carry out, motives for, and targets of a DoS attack may vary, it generally consists of the concerted efforts of a person or people to prevent an Internet site or service from functioning efficiently or at all, temporarily or indefinitely.

"SQL Injection" is subset of an unverified user input vulnerability ("buffer overflows" are a different subset), and the idea is to convince the application to run SQL code that was not intended. If the application is creating SQL strings naively on the fly and then running them, it’s straightforward to create some real surprises.

On this article i will show how to find the default values. The sys.objects and sys.columns provides us with the metadata needed to find the default values of all columns in a database.

Inner join, Joining Three or More Tables , Outer join,Left outer join,Right outer join, Full outer join, Correlated Subquery