Search Results
https://dev.mysql.com/doc/refman/8.4/en/partitioning-handling-nulls.html
Partitioning in MySQL does nothing to disallow NULL as the value of a partitioning expression, whether it is a column value or the value of a user-supplied expression. MySQL's partitioning implementation treats NULL as being less than any non-NULL ...Even though it is permitted to use NULL as the value of an expression that must otherwise yield an integer, it is important to keep in mind that NULL is not a ...
https://dev.mysql.com/doc/refman/8.4/en/partitioning-pruning.html
The optimization known as partition pruning is based on a relatively simple concept which can be described as “Do not scan partitions where there can be no matching values”. By limiting the search, it is possible to expend much less time and ...
https://dev.mysql.com/doc/refman/8.4/en/partitioning-types.html
This section discusses the types of partitioning which are available in MySQL 8.4. This type of partitioning assigns rows to partitions based on column values falling within a given range. For information about an extension to this type, RANGE ...
https://dev.mysql.com/doc/refman/8.4/en/information-schema-partitions-table.html
Each row in this table corresponds to an individual partition or subpartition of a partitioned table. The PARTITIONS table has these columns: TABLE_CATALOG The name of the catalog to which the table belongs. SUBPARTITION_NAME If the PARTITIONS table ...TABLE_SCHEMA The name of the schema (database) to which the table ...
https://dev.mysql.com/doc/refman/8.4/en/partitioning-maintenance.html
A number of table and partition maintenance tasks can be carried out on partitioned tables using SQL statements intended for such purposes. Table maintenance of partitioned tables can be accomplished using the statements CHECK TABLE, OPTIMIZE ...
https://dev.mysql.com/doc/refman/8.4/en/partitioning-list.html
List partitioning in MySQL is similar to range partitioning in many ways. As in partitioning by RANGE, each partition must be explicitly defined. The chief difference between the two types of partitioning is that, in list partitioning, each ...For ...
https://dev.mysql.com/doc/refman/8.4/en/partitioning-key.html
Partitioning by key is similar to partitioning by hash, except that where hash partitioning employs a user-defined expression, the hashing function for key partitioning is supplied by the MySQL server. PARTITION BY KEY are similar to those for ...
https://dev.mysql.com/doc/refman/8.4/en/partitioning-management.html
There are a number of ways using SQL statements to modify partitioned tables; it is possible to add, drop, redefine, merge, or split existing partitions using the partitioning extensions to the ALTER TABLE statement. There are also ways to obtain ...
https://dev.mysql.com/doc/refman/8.4/en/partitioning-info.html
This section discusses obtaining information about existing partitions, which can be done in a number of ways. Methods of obtaining such information include the following: Using the SHOW CREATE TABLE statement to view the partitioning clauses used ...The rows column of EXPLAIN output displays the total number of rows in the ...
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 ...