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What does optimize table do in MySQL?
OPTIMIZE TABLE reorganizes the physical storage of table data and associated index data, to reduce storage space and improve I/O efficiency when accessing the table. The exact changes made to each table depend on the storage engine used by that table.
How long does optimize table take?
Optimizing table straight away takes over 3 hours, while dropping indexes besides primary key, optimizing table and adding them back takes about 10 minutes, which is close than 20x speed difference and more compact index in the end.
Is optimize table Safe?
Outside of an Earthquake or Power Outage, running OPTIMIZE TABLE does not harm to the data and indexes get rebuilt.
Do InnoDB tables need to be optimized?
Doing optimize table on an InnoDB table is usually not necessary to do frequently, but only after you do a lot of insert/update/delete against the table in a way that could result in fragmentation. ANALYZE TABLE is much less impact for InnoDB. This doesn’t require building a copy of the table.
How does optimize table work?
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. For InnoDB tables, optimize table will simply perform an alter table to reclaim the space.
What does optimize table do in phpMyAdmin?
It’s very easy to optimize databases using the DB optimize tool found in phpMyAdmin. Using this tool is similar to defragmenting a computer, and can shrink a database’s size and remove unused elements that are left behind from frequent changes, referred to as overhead.
How do I repair a mySQL table?
Use this procedure to repair MySQL tables from the command line: Log in to the server using SSH. From the command line, enter this command, replacing [username] with your username and without the brackets: mysql -u [username] -p Enter your password. Again, without the brackets, enter the command: use [databasename]; Enter the command: show tables;
How to get list of MySQL views?
Connect to the database server.
What is the name of MySQL database?
MySQL ( /ˌmaɪˌɛsˌkjuːˈɛl/ “My S-Q-L”) is an open-source relational database management system (RDBMS). Its name is a combination of “My”, the name of co-founder Michael Widenius ‘s daughter, and ” SQL “, the abbreviation for Structured Query Language .