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https://dev.mysql.com/doc/refman/8.4/en/mysqlcheck.html
The mysqlcheck client performs table maintenance: It checks, repairs, optimizes, or analyzes tables. Each table is locked and therefore unavailable to other sessions while it is being processed, although for check operations, the table is locked ...
https://dev.mysql.com/doc/refman/8.4/en/mysqldump-delimited-text.html
This section describes how to use mysqldump to create delimited-text dump files. For information about reloading such dump files, see Section 9.4.4, “Reloading Delimited-Text Format Backups”. If you invoke mysqldump with the --tab=dir_name ...
https://dev.mysql.com/doc/refman/8.4/en/mysqlshow.html
The mysqlshow client can be used to quickly see which databases exist, their tables, or a table's columns or indexes. The same information can be obtained by using those statements directly. For example, you can issue them from the mysql client ...
https://dev.mysql.com/doc/refman/8.4/en/null-values.html
The NULL value means “no data.” NULL can be written in any lettercase. Be aware that the NULL value is different from values such as 0 for numeric types or the empty string for string types. For text file import or export operations performed ...
https://dev.mysql.com/doc/refman/8.4/en/optimizing-innodb-storage-layout.html
Once your data reaches a stable size, or a growing table has increased by tens or some hundreds of megabytes, consider using the OPTIMIZE TABLE statement to reorganize the table and compact any wasted space. The reorganized tables require less disk ...
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/performance-schema-error-summary-tables.html
The Performance Schema maintains summary tables for aggregating statistical information about server errors (and warnings). For a list of server errors, see Server Error Message Reference. Collection of error information is controlled by the error ...
https://dev.mysql.com/doc/refman/8.4/en/performance-schema-host-cache-table.html
The MySQL server maintains an in-memory host cache that contains client host name and IP address information and is used to avoid Domain Name System (DNS) lookups. The host_cache_size system variable controls the size of the host cache, as well as ...
https://dev.mysql.com/doc/refman/8.4/en/performance-schema-setup-metrics-table.html
The setup_metrics table lists the available metrics: mysql> select * from performance_schema.setup_metrics\G *************************** 34. row *************************** NAME: undo_tablespaces_active METER: mysql.inno METRIC_TYPE: ASYNC GAUGE ...
https://dev.mysql.com/doc/refman/8.4/en/program-variables.html
Many MySQL programs have internal variables that can be set at runtime using the SET statement. See Section 15.7.6.1, “SET Syntax for Variable Assignment”, and Section 7.1.9, “Using System Variables”. Most of these program variables also ...