ShellHacks

It is often required to get the size of a database in MySQL to understand how much disk space does it need.

It is especially useful to check the size of a database if you prepare to migrate it somewhere or going to setup database backup and it needs to choose the storage capacity.

In this short note i will show the SQL queries that get the information about the required databases from the information_schema and print their sizes in megabytes. (more…)

While working with MySQL databases, it is often required to find out the total number of rows in some table.

There are many different ways to count the table rows in MySQL, but as the performance always matters, the fastest way is the most preferable.

Below you will find the best and the fastest way to get the number of rows in a table using the simple SQL query. (more…)

Sometimes it is required to find out the size of a table in MySQL database.

For example, if it is needed to perform an optimization and you analyze if some tables have become too large and it is time to tweak them somehow.

In this short note i will show the SQL query that gets the information about the required table from the information_schema and prints the table’s size in megabytes. (more…)

Sometimes it is required to compare two tables to check if they are the same or not.

For this you can calculate and compare the checksums of each table, using the CHECKSUM TABLE command in MySQL.

This command is especially useful if you’re using MySQL replication and want to ensure that master and slave are consistent by verifying that their tables are identical. (more…)