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https://dev.mysql.com/doc/refman/8.4/en/compressed-format.html
If a column has only a small set of possible values, the data type is converted to ENUM. Compressed storage format is a read-only format that is generated with the myisampack tool. Compressed tables have the following characteristics: Compressed ...
https://dev.mysql.com/doc/refman/8.4/en/dynamic-system-variables.html
Variables that are marked as “enumeration” normally should be set to one of the available values for the variable, but can also be set to the number that corresponds to the desired enumeration value. For enumerated system variables, the first ...
https://dev.mysql.com/doc/refman/8.4/en/engine-condition-pushdown-optimization.html
This exclusion extends to JSON, BIT, and ENUM columns as well. This optimization improves the efficiency of direct comparisons between a nonindexed column and a constant. In such cases, the condition is “pushed down” to the storage engine for ...
https://dev.mysql.com/doc/refman/8.4/en/example-auto-increment.html
You can also explicitly assign 0 to the column to generate sequence numbers, unless the NO_AUTO_VALUE_ON_ZERO SQL mode is enabled. For example: INSERT INTO animals (id,name) VALUES(0,'groundhog'); If the column is declared NOT NULL, it is also ...
https://dev.mysql.com/doc/refman/8.4/en/extensions-to-ansi.html
Data types The MEDIUMINT, SET, and ENUM data types, and the various BLOB and TEXT data types. MySQL Server supports some extensions that you are not likely to find in other SQL DBMSs. Be warned that if you use them, your code is most likely not ...
https://dev.mysql.com/doc/refman/8.4/en/features.html
Data Types Many data types: signed/unsigned integers 1, 2, 3, 4, and 8 bytes long, FLOAT, DOUBLE, CHAR, VARCHAR, BINARY, VARBINARY, TEXT, BLOB, DATE, TIME, DATETIME, TIMESTAMP, YEAR, SET, ENUM, and OpenGIS spatial types. This section describes some ...
https://dev.mysql.com/doc/refman/8.4/en/flow-control-functions.html
SET and ENUM are treated similar to VARCHAR; the result is VARCHAR. The second syntax returns the result for the first condition that is true. If no comparison or condition is true, the result after ELSE is returned, or NULL if there is no ELSE part. Note The syntax of the CASE operator described here differs slightly from that of the SQL CASE statement described in Section 15.6.5.1, “CASE Statement”, for use inside stored ...
https://dev.mysql.com/doc/refman/8.4/en/information-schema-table-constraints-table.html
The TABLE_CONSTRAINTS table has these columns: CONSTRAINT_CATALOG The name of the catalog to which the constraint belongs. CONSTRAINT_SCHEMA The name of the schema (database) to which the constraint belongs. TABLE_SCHEMA The name of the schema ...
https://dev.mysql.com/doc/refman/8.4/en/innodb-page-compression.html
InnoDB supports page-level compression for tables that reside in file-per-table tablespaces. Page compression is enabled by specifying the COMPRESSION attribute with CREATE TABLE or ALTER TABLE. Supported Platforms Page compression requires sparse ...
https://dev.mysql.com/doc/refman/8.4/en/json-attribute-functions.html
The functions in this section return attributes of JSON values. An error occurs if the argument is not a valid JSON document. An empty array, empty object, or scalar value has depth 1. A nonempty array containing only elements of depth 1 or ...