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https://dev.mysql.com/doc/refman/8.4/en/myisamchk-table-info.html
varchar prefix 0 1024 87 80 varchar 0 3 168 3 multip. uint24 NULL 0 1024 Field Start Length Nullpos Nullbit Type 1 1 1 2 2 4 no zeros 3 6 81 varchar 4 87 81 varchar 5 168 3 1 1 no zeros 6 171 3 1 2 no zeros Explanations for the types of information ... To obtain a description of a MyISAM table or statistics about it, use the commands shown ...
https://dev.mysql.com/doc/refman/8.4/en/mysql-cluster-disk-data-storage-requirements.html
For example, converting a CHAR(4) column from memory-based to disk-based format increases the amount of DataMemory used per row from 4 to 8 bytes. The following items apply to Disk Data storage requirements: Variable-length columns of Disk Data ...
https://dev.mysql.com/doc/refman/8.4/en/mysql-cluster-limitations-database-objects.html
For memory-based columns, you can work around this limitation by using a variable-width column type such as VARCHAR or defining the column as COLUMN_FORMAT=DYNAMIC; this does not work with columns stored on disk. Some database objects such as ...
https://dev.mysql.com/doc/refman/8.4/en/numeric-type-attributes.html
For example, applications can use the LPAD() function to zero-pad numbers up to the desired width, or they can store the formatted numbers in CHAR columns. MySQL supports an extension for optionally specifying the display width of integer data ...
https://dev.mysql.com/doc/refman/8.4/en/numeric-type-syntax.html
For example, applications could use the LPAD() function to zero-pad numbers up to the desired width, or they could store the formatted numbers in CHAR columns. For integer data types, M indicates the minimum display width. Display width is ...
https://dev.mysql.com/doc/refman/8.4/en/order-by-optimization.html
For example, if only the first 10 bytes of a CHAR(20) column are indexed, the index cannot distinguish values past the 10th byte and a filesort is needed. Separate the paths by colon characters (:) on Unix and semicolon characters (;) on Windows.
https://dev.mysql.com/doc/refman/8.4/en/partitioning-columns.html
The next two sections discuss COLUMNS partitioning, which are variants on RANGE and LIST partitioning. COLUMNS partitioning enables the use of multiple columns in partitioning keys. All of these columns are taken into account both for the purpose ...
https://dev.mysql.com/doc/refman/8.4/en/partitioning-hash.html
Partitioning by HASH is used primarily to ensure an even distribution of data among a predetermined number of partitions. To partition a table using HASH partitioning, it is necessary to append to the CREATE TABLE statement a PARTITION BY HASH ...
https://dev.mysql.com/doc/refman/8.4/en/partitioning-linear-hash.html
MySQL also supports linear hashing, which differs from regular hashing in that linear hashing utilizes a linear powers-of-two algorithm whereas regular hashing employs the modulus of the hashing function's value. We call this value V; it can be ...
https://dev.mysql.com/doc/refman/8.4/en/performance-schema-user-defined-functions-table.html
The value is one of int, decimal, real, char, or row. The user_defined_functions table contains a row for each loadable function registered automatically by a component or plugin, or manually by a CREATE FUNCTION statement. For information about ...