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https://dev.mysql.com/doc/refman/8.4/en/local-variable-scope.html
The scope of a local variable is the BEGIN ... The variable can be referred to in blocks nested within the declaring block, except those blocks that declare a variable with the same name. Because local variables are in scope only during stored ...
https://dev.mysql.com/doc/refman/8.4/en/lock-tables.html
LOCK {TABLE | TABLES} tbl_name [[AS] alias] lock_type [, tbl_name [[AS] alias] lock_type] ... lock_type: { READ [LOCAL] | WRITE } UNLOCK {TABLE | TABLES} MySQL enables client sessions to acquire table locks explicitly for the purpose of cooperating ...
https://dev.mysql.com/doc/refman/8.4/en/merge-storage-engine.html
The MERGE storage engine, also known as the MRG_MyISAM engine, is a collection of identical MyISAM tables that can be used as one. “Identical” means that all tables have identical column data types and index information. You cannot merge MyISAM ...
https://dev.mysql.com/doc/refman/8.4/en/metadata-locking.html
MySQL uses metadata locking to manage concurrent access to database objects and to ensure data consistency. Metadata locking applies not just to tables, but also to schemas, stored programs (procedures, functions, triggers, scheduled events), ...
https://dev.mysql.com/doc/refman/8.4/en/myisampack.html
When the table is used later, the server reads into memory the information needed to decompress columns. This results in much better performance when accessing individual rows, because you only have to uncompress exactly one row. MySQL uses mmap() ...
https://dev.mysql.com/doc/refman/8.4/en/mysql-cluster-install-linux-binary.html
This section covers the steps necessary to install the correct executables for each type of Cluster node from precompiled binaries supplied by Oracle. For setting up a cluster using precompiled binaries, the first step in the installation process ...
https://dev.mysql.com/doc/refman/8.4/en/mysqlbinlog-row-events.html
The following examples illustrate how mysqlbinlog displays row events that specify data modifications. These correspond to events with the WRITE_ROWS_EVENT, UPDATE_ROWS_EVENT, and DELETE_ROWS_EVENT type codes. The --base64-output=DECODE-ROWS and ...
https://dev.mysql.com/doc/refman/8.4/en/parenthesized-query-expressions.html
parenthesized_query_expression: ( query_expression [order_by_clause] [limit_clause] ) [order_by_clause] [limit_clause] [into_clause] query_expression: query_block [set_op query_block [set_op query_block ...]] [order_by_clause] [limit_clause] ...
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 ...
https://dev.mysql.com/doc/refman/8.4/en/performance-schema-transaction-tables.html
Within the event hierarchy, wait events nest within stage events, which nest within statement events, which nest within transaction events. These tables store transaction events: events_transactions_current: The current transaction event for each ...