Saturday, June 30, 2012

Creating and dropping indexes in MySQL table

Indexes increases the speed of select queries. At the same time indexes decreases the insert query performance if there are lots of indexes in a table. How to add an index to MySQL table  and how to drop an index from a MySQL table? We will discuss both in this article.

For showing indexes in a table we can use show indexes from command. In this we can see that there is only one index that is primary index in the table based on the column employee_id

Benchmarking MySQL with mysqlslap

I have been checking with different tools for benchmarking a mysql server. I went through a lot of blogs and manuals and decided to use a tool named mysqlslap. In this post we will discuss how to install mysqlslap and use it. We are using Centos Linux 5.4 to test this.

Luckily mysqlslap comes with mysql-client rpm itself. With the versions 5.1.4 and above. So you can either install mysql with yum or rpm. rpms are available on for download.

I have tested it with MySQL-client-5.5.25-1.rhel5.i386.rpm.
Just install it as 
#rpm -ivh MySQL-client-5.5.25-1.rhel5.i386.rpm
Then you will get the command "mysqlslap"

Thursday, June 28, 2012

importing csv file to MySQL database table

Sometimes we need to get the MySQL tables into an Excel sheet. How this can be done? We can dump the MySQL tables into a csv format file. It is explained in our previous post Dumping MySQL table into CSV file. But how to import a csv file to a mysql database table? We will discuss it in this post.

Login to your MySQL server.
[root@database ~]# mysql -p
Enter password: