Contents
How to optimize MySQL tables and defragment to recover space?
Few points to keep in mind about optimize table: Optimize table can be performed for InnoDB engine, or MyISAM engine, or ARCHIVE tables. For MyISAM tables, it will analyze the table, it will defragment the corresponding MySQL datafile, and reclaim the unused space.
Which is the best way to defragment a table?
For more information, see Section 14.13, “InnoDB and Online DDL” . Another way to perform a defragmentation operation is to use mysqldump to dump the table to a text file, drop the table, and reload it from the dump file.
Which is a symptom of fragmentation in MySQL?
Another symptom of fragmentation is that a table scan such as this takes more time than it “should” take: The preceding query requires MySQL to perform a full table scan, the slowest type of query for a large table. To speed up index scans, you can periodically perform a “null” ALTER TABLE operation, which causes MySQL to rebuild the table:
How to optimize all the tables in MySQL?
If you want to optimize all the tables in a particular MySQL database, use the following command. The following command will optimize all the tables located in thegeekstuff database. mysqlcheck -o thegeekstuff -u root -pMySQLSecretPwd99
Which is the best way to optimize a table?
There are two ways to optimize a table. The first method is to use Optimize table command as shown below. The following example will optimize EMPLOYEE table. You can also optimize multiple tables in a single command as shown below. Few points to keep in mind about optimize table:
What is the difference between OPTIMIZE TABLE and analyze table in MySQL?
ANALYZE TABLE examines key distribution and stores them in INFORMATION_SCHEMA.STATISTICS. OPTIMIZE TABLE performs ANALYZE TABLE after doing some table compression. The equivalent of OPTIMIZE TABLE mydb.mytable; if the table was MyISAM is this: For the MyISAM table mydb.mytable in datadir /var/lib/mysql, you have the following files:
How to know how much space is available in MySQL?
Connect to your MySQL database, and execute the following query, which will display how much unused space are available in every table. This will display list of all tables that has minimum of 500MB of unused space.
How to tune and optimize performance of MySQL 5.7?
Run the commands below to install tuning primer: The tuning of MySQL server is done on MySQL configuration file. Run mysqltuner.
How to tune MySQL performance with Perl script?
MySQLTuner is a Perl script that analyzes your MySQL performance and, based on the statistics it gathers, gives recommendations which variables you should adjust in order to increase performance. That way, you can tune your my.cnf file to tease out the last bit of performance from your MySQL server and make it work more efficiently.