![]() So optimize your MySQL tables only after detailed analysis of its query performance and space consumption.MySQL and MariaDB are popular choices for database management systems. Nevertheless, you need to be careful before you run the optimization since it can lock the table for a long time. However, if you are using really large tables, you may need to optimize them once in a while, especially if they are transactional tables that are written frequently. In most cases, MySQL automatically manages databases and queries very well, without any need for optimization. In this article, we have learnt how to optimize tables in MySQL. Once the optimization is complete, you can run the SQL queries mentioned in step 1, to see the difference. mysql> sudo mysqlcheck -o -u -p ĭuring optimization, MySQL will free up unused allocated memory as well as improve database’s overall memory. Replace with your database schema, with table name you want to optimize, with database username, and with database password. You can also optimize MySQL tables from terminal, with the following command. You need to list them one after the other in a comma-separated manner. Here is the command to optimize multiple MySQL tables. ![]() When optimization is a complete, the above command will give a simple output displaying the results. The optimize command, locks the table, creates a temporary copy of it, optimizes this temporary copy and replaces the original table with the temporary table, and releases the lock added earlier. Replace with the name of table that you want to optimize. Here is the syntax for optimizing tables. Now we will look at how to optimize MySQL tables. If you want to see the data_length and data_free in MB (megabytes), modify the above query as shown below. Now the above query’s output will be in no. If you want to see the above information for all tables in all databases, exclude the WHERE clause in it. ![]() All this metadata information is stored in information_schema table, for each table in all your databases in the system. It will display table name, the space occupied and free space for each table in your database. mysql> select table_name, data_length, data_free If you want to list the unallocated space for each table, run the following command. By default, MySQL allocates a certain space for each table. It helps us determine which table requires optimization. Data_free – amount of unallocated space in database table.Data_length – amount of total space occupied by the tables.In the output, look for two parameters mentioned below Replace with your table’s name, mysql> show table status like "" \G Next, run the following command, on your table that you think might be suitable for optimization. In such cases, you should optimize only secondary indexes and not the primary ones.įirst connect to your database. Generally, it is the secondary indexes that cause problems and not the primary index. It is also important to know which value to optimize.If you find that your tables work properly even without indexing for some time, then you can drop the index from a table, optimize it, and then add the index back.So before you optimize tables, you can also try the following tricks to see if it improves performance Since transactional tables are generally the ones that need optimization, you need to plan in advance before you run the following optimizations, since they will most likely lock your tables when they are running. If your MySQL database takes up a lot more space than it should, or takes a lot more time to process queries, than it should, then you should try to optimize them.īut it is important to note that database optimization can take a long time, depending on the size of tables and amount of optimization needed. That is very useful to database management and maintenance. In this article, we will learn the different MySQL optimizations and also when to use them. There are several different types of optimizations available for MySQL tables. In such cases, you may need to optimize MySQL tables. Sometimes you may find that MySQL queries and performance has slowed down over time.
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