What is InnoDB redo log?

The redo log is a disk-based data structure used during crash recovery to correct data written by incomplete transactions. 2, “InnoDB Recovery”. By default, the redo log is physically represented on disk by two files named ib_logfile0 and ib_logfile1 . MySQL writes to the redo log files in a circular fashion.

Is it safe to delete ib_logfile0?

The ib_logfile* files are needed for InnoDB crash recovery. If you shut down InnoDB cleanly, you can remove them and change their size in the configuration file. Of course, you should be careful when doing such changes. It is best to take backups first.

How does MySQL InnoDB work?

InnoDB tables arrange your data on disk to optimize queries based on primary keys. Each InnoDB table has a primary key index called the clustered index that organizes the data to minimize I/O for primary key lookups. See Section 14.6. To maintain data integrity, InnoDB supports FOREIGN KEY constraints.

Does MySQL have a log file?

By default no log files are enabled in MYSQL. All errors will be shown in the syslog ( /var/log/syslog ).

What is the purpose of redo log files?

Redo log files are operating system files used by Oracle to maintain logs of all transactions performed against the database. The primary purpose of these log files is to allow Oracle to recover changes made to the database in the case of a failure.

What are undo and redo logs in MySQL?

Yes, UNDO and REDO logs are the 2 different kind of logs; each with it’s own purpose and you shouldn’t get confused between them ..!! As the name indicates, REDO logs are for Re-doing things..! The transactions which were already executed, but not committed the disk due to some DB crash..!

Is InnoDB a database?

InnoDB is a storage engine for the database management system MySQL and MariaDB. Since the release of MySQL 5.5….InnoDB.

Where are MySQL logs stored?

The default location for each of the logs is the MySQL Data directory (C:\ProgramData\MySQL\MySQL Server [version number]\Data\), and the default log names are based on the computer’s device name.

How do I delete a MySQL log file?

How to remove and purge old MySQL binary log files

1. Step 1: Check binary logs size under the dump directory.
2. Step 2:Connect DB and show MySQL binary logs.
3. Step 3: Remove old Binary logs.

How do I recover a redo log file?

To recover from loss of an active online redo log group in ARCHIVELOG mode:

1. Begin incomplete media recovery.
2. Ensure that the current name of the lost redo log can be used for a newly created file.
3. Open the database using the RESETLOGS option: