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https://dev.mysql.com/doc/refman/8.4/en/create-table.html
When you insert a value of NULL (recommended) or 0 into an indexed AUTO_INCREMENT column, the column is set to the next sequence value. Take this into account when specifying a prefix length for a nonbinary string column that uses a multibyte ...| ...
MySQL 8.4 Reference Manual :: A.11 MySQL 8.4 FAQ: MySQL Chinese, Japanese, and Korean Character Sets
https://dev.mysql.com/doc/refman/8.4/en/faqs-cjk.html
Where can I find translations of the MySQL Manual into Chinese, Japanese, and Korean? A.11.19. Sometimes people try to insert gbk characters into gb2312, and it works most of the time because gbk is a superset of gb2312. mysql> SET sql_mode = ''; ...
https://dev.mysql.com/doc/refman/8.4/en/index-preloading.html
Preloading enables you to put the table index blocks into a key cache buffer in the most efficient way: by reading the index blocks from disk sequentially. Without preloading, the blocks are still placed into the key cache as needed by queries. To ... If there are enough blocks in a key cache to hold blocks of an entire index, or at least the blocks corresponding to its nonleaf nodes, it makes sense to preload the key cache with index blocks before starting to use ...
https://dev.mysql.com/doc/refman/8.4/en/innodb-fulltext-index.html
When incoming documents are tokenized, the individual words (also referred to as “tokens”) are inserted into the index tables along with position information and an associated DOC_ID. The inverted index is partitioned into six auxiliary index ...
https://dev.mysql.com/doc/refman/8.4/en/invisible-columns.html
Reloading a dump file into an older version of MySQL that does not support invisible columns causes the version-specific comment to be ignored, which creates any invisible columns as visible. An invisible column is normally hidden to queries, but ...
https://dev.mysql.com/doc/refman/8.4/en/join.html
This includes a join handled by merging derived tables and views in the FROM clause into the outer query block (see Section 10.2.2.4, “Optimizing Derived Tables, View References, and Common Table Expressions with Merging or Materialization”).
https://dev.mysql.com/doc/refman/8.4/en/load-data-local-security.html
The LOAD DATA statement loads a data file into a table. For client programs that use the C API, local data loading capability is determined by the default compiled into the MySQL client library. For the mysql client, local data loading capability ...The statement can load a file located on the server host, or, if the LOCAL keyword is specified, on the client ...
https://dev.mysql.com/doc/refman/8.4/en/merge-table-problems.html
Instead, the rows from the underlying MyISAM tables are copied into the altered table, which then uses the specified storage engine. The INSERT_METHOD table option for a MERGE table indicates which underlying MyISAM table to use for inserts into the ... The following are known problems with MERGE tables: MERGE child tables are locked through the parent ...
https://dev.mysql.com/doc/refman/8.4/en/mysql-cluster-replication-schema.html
Splitting replication streams into two (or more) binary logs can be done for reasons of performance, a need to replicate different databases to different places, use of different binary logging types for different databases, and so on.
https://dev.mysql.com/doc/refman/8.4/en/optimizer-hints.html
Whether derived tables, view references, or common table expressions should be merged into the outer query block, or materialized using an internal temporary table. If one subquery is nested within another and both are merged into a semijoin of an ... One means of control over optimizer strategies is to set the optimizer_switch system variable (see Section 10.9.2, “Switchable ...