MySQL Server parameter description and viewing setting method

View parameters: Show variables;
Set parameter: set global parameter name = value. For example, set the maximum number of connections to a database to set global max_connections = 1000.

Use the shell> mysqld-HELP command to obtain a table with all MySQL options and configurable variables. The following information is output:
Possible variables for option -- Set-variable (-O) are:
Back_log current value: 5 // the number of connections that MySQL can have. back_log indicates how many connection requests can be stored in the stack during the time when MySQL suspends the connection.
Connect_timeout current value: 5 // MySQL Server waits for a connection time before responding with bad handshake
Delayed_insert_timeout current value: 200 // The time for an insert delayed to wait for the Insert before termination
Delayed_insert_limit current value: 50 // The insert delayed processor checks whether any select statements are not executed. If yes, run these statements before resuming.
Delayed_queue_size current value: 1000 // the size of the queue allocated for insert delayed
Flush_time current value: 0 // if it is set to a non-0 value, all tables are closed for each flush_time.
Interactive_timeout current value: 28800 // time the server waits for a foreign interactive connection before closing it
Join_buffer_size current value: 131072 // the buffer size connected to all
Key_buffer_size current value: 1048540 // the buffer size of the clause index block. You can increase it to better process the index.
Lower_case_table_names current value: 0 //
Long_query_time current value: 10 // If a query takes more time than this time, the slow_queried count will increase
Max_allowed_packet current value: 1048576 // size of a package
Max_connections current value: 300 // number of concurrent connections allowed
Max_connect_errors current value: 10 // if there are more than this number of interrupted connections, further connections will be blocked. You can use flush hosts to solve this problem.
Max_delayed_threads current value: 15 // Number of insert delayed processes that can be started
Max_heap_table_size current value: 16777216 //
Max_join_size current value: 4294967295 // Number of connections that can be read
Max_sort_length current value: 1024 // number of bytes used for sorting blob or text
Max_tmp_tables current value: 32 // number of temporary tables simultaneously opened by a connection
Max_write_lock_count current value: 4294967295 // specify a value (usually very small) to start mysqld, so that the read lock occurs after a certain number of write locks.
Net_buffer_length current value: 16384 // communication buffer size -- reset to this size during Query
Query_buffer_size current value: 0 // buffer size during Query
Record_buffer current value: 131072 // size of the buffer allocated to each table scanned by connections for each Sequential Scan
Sort_buffer current value: 2097116 // size of the buffer allocated for each sort connection
Table_cache current value: 64 // number of tables opened for all connections
Thread_concurrency current value: 10 //
Tmp_table_size current value: 1048576 // temporary table size
Thread_stack current value: 131072 // the size of each thread
Wait_timeout current value: 28800 // time the server waits for a connection before closing it 3