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https://dev.mysql.com/doc/refman/8.4/en/no-matching-rows.html
If you still cannot figure out what is wrong, create a minimal test that can be run with mysql test < query.sql that shows your problems. You can create a test file by dumping the tables with mysqldump --quick db_name tbl_name_1 ... Verify that the ... If you have a complicated query that uses many tables but that returns no rows, you should use the following procedure to find out what is wrong: Test the query with EXPLAIN to check whether you can find something that is obviously ...
https://dev.mysql.com/doc/refman/8.4/en/online-ddl-memory-management.html
Online DDL operations that create or rebuild secondary indexes allocate temporary buffers during different phases of index creation. The setting applies to buffers created by threads executing online DDL operations. Defining an appropriate buffer ...The innodb_ddl_buffer_size variable defines the maximum buffer size for online DDL ...
https://dev.mysql.com/doc/refman/8.4/en/partitioning-linear-hash.html
MySQL also supports linear hashing, which differs from regular hashing in that linear hashing utilizes a linear powers-of-two algorithm whereas regular hashing employs the modulus of the hashing function's value. We call this value V; it can be ...
https://dev.mysql.com/doc/refman/8.4/en/partitioning-management-hash-key.html
Tables which are partitioned by hash or by key are very similar to one another with regard to making changes in a partitioning setup, and both differ in a number of ways from tables which have been partitioned by range or list. For that reason, ...
https://dev.mysql.com/doc/refman/8.4/en/problems-with-float.html
Suppose that you execute the following statements: CREATE TABLE t1(c1 FLOAT(53,0), c2 FLOAT(53,0)); INSERT INTO t1 VALUES('1e+52','-1e+52'); SELECT * FROM t1; On some platforms, the SELECT statement returns inf and -inf. An implication of the ...
https://dev.mysql.com/doc/refman/8.4/en/programs-overview.html
mysqladmin A client that performs administrative operations, such as creating or dropping databases, reloading the grant tables, flushing tables to disk, and reopening log files. Oracle Corporation also provides the MySQL Workbench GUI tool, which ...Later sections provide a more detailed description of each one, with the exception of NDB Cluster ...
https://dev.mysql.com/doc/refman/8.4/en/rebuilding-tables.html
If you need to rebuild an InnoDB table because a CHECK TABLE operation indicates that a table upgrade is required, use mysqldump to create a dump file and mysql to reload the file. For example, if t1 is an InnoDB table, use this statement: ALTER ...
https://dev.mysql.com/doc/refman/8.4/en/replication-features-directory.html
If a DATA DIRECTORY or INDEX DIRECTORY table option is used in a CREATE TABLE statement on the source server, the table option is also used on the replica. This can be overridden by using the NO_DIR_IN_CREATE server SQL mode on the replica, which ...This can cause problems if no corresponding directory exists in the replica host file system or if it exists but is not accessible to the replica MySQL ...
https://dev.mysql.com/doc/refman/8.4/en/replication-features-load-data.html
If you use LOAD DATA with binlog_format=STATEMENT, each replica on which the changes are to be applied creates a temporary file containing the data. This temporary file is not encrypted, even if binary log encryption is active on the source, If ...
https://dev.mysql.com/doc/refman/8.4/en/scheduler-component.html
When a caller invokes the mysql_scheduler.create() service, it creates a new scheduled task instance to add to the queue, which signals the semaphore of the background thread. When the caller invokes destroy() and passes in the handle it received ...