https://dev.mysql.com/internal-temporary-tables.html
When in-memory internal temporary tables are managed by the MEMORY storage engine, fixed-length row format is used. Columns take only as much storage as needed, which reduces disk I/O, space requirements, and processing time compared to on-disk ...
https://dev.mysql.com/selecting-all.html
Fix only the erroneous record with an UPDATE statement: mysql> UPDATE pet SET birth = '1989-08-31' WHERE name = 'Bowser'; The UPDATE changes only the record in question and does not require you to reload the table. For example, you may happen to ...
https://dev.mysql.com/data-types.html
For floating-point and fixed-point types, M is the total number of digits that can be stored (the precision). D applies to floating-point and fixed-point types and indicates the number of digits following the decimal point (the scale). MySQL ...
https://dev.mysql.com/plugin-data-structures.html
The descriptor begins with a fixed set of members common to all client plugins, followed by any members specific to the plugin type. For example, if a program needs to use a client authentication plugin named auth_xxx on a system that uses .so as ...
https://dev.mysql.com/mysql-cluster-programs-ndb-size-pl.html
This is a Perl script that can be used to estimate the amount of space that would be required by a MySQL database if it were converted to use the NDBCLUSTER storage engine. Unlike the other utilities discussed in this section, it does not require ...
https://dev.mysql.com/group-replication-frequently-asked-questions.html
You need to find out why a member is lagging behind and fix that or remove the member from the group. Alternatively, another way of fixing the issue specifically in Group Replication is to issue a STOP GROUP_REPLICATION statement and then a START ...
https://dev.mysql.com/dynamic-format.html
If you have fixed-length columns that you access or change frequently in a table that also contains some variable-length columns, it might be a good idea to move the variable-length columns to other tables just to avoid fragmentation. Much less disk ... Dynamic storage format is used if a MyISAM table contains any variable-length columns (VARCHAR, VARBINARY, BLOB, or TEXT), or if the table was created with the ROW_FORMAT=DYNAMIC table ...
https://dev.mysql.com/upgrading-from-previous-series.html
Several spatial functions were removed in MySQL 8.0.0 due to a spatial function namespace change that implemented an ST_ prefix for functions that perform an exact operation, or an MBR prefix for functions that perform an operation based on minimum ... Before upgrading to MySQL 8.0, review the changes described in this section to identify those that apply to your current MySQL installation and ...
https://dev.mysql.com/memory-storage-engine.html
Variable-length types such as VARCHAR are stored using a fixed length. The MEMORY storage engine (formerly known as HEAP) creates special-purpose tables with contents that are stored in memory. Because the data is vulnerable to crashes, hardware ...
https://dev.mysql.com/char.html
The length of a CHAR column is fixed to the length that you declare when you create the table. In contrast to CHAR, VARCHAR values are stored as a 1-byte or 2-byte length prefix plus data. The length prefix indicates the number of bytes in the value. InnoDB encodes fixed-length fields greater than or equal to 768 bytes in length as variable-length fields, which can be stored ...