全局内存和session内存

查看全局内存和session内存使用情况

参考:https://dev.mysql.com/doc/refman/8.0/en/memory-use.html

-- 排除了innodb_additional_mem_pool_size

SELECT ( @@key_buffer_size
+ @@query_cache_size
+ @@innodb_buffer_pool_size
+ @@innodb_log_buffer_size
+ @@max_connections * ( @@read_buffer_size
+ @@read_rnd_buffer_size
+ @@sort_buffer_size
+ @@join_buffer_size
+ @@binlog_cache_size
+ @@thread_stack
+ @@tmp_table_size )
) / (1024 * 1024 * 1024) AS MAX_MEMORY_GB
,@@innodb_buffer_pool_size / (1024 * 1024 * 1024) as innodb_buffer_pool_size_GB
,@@max_connections as max_connections
,( @@read_buffer_size
+ @@read_rnd_buffer_size
+ @@sort_buffer_size
+ @@join_buffer_size
+ @@binlog_cache_size
+ @@thread_stack
+ @@tmp_table_size ) / (1024 * 1024 ) as session_all_MB
,@@tmp_table_size    / (1024 * 1024 ) as tmp_table_size_MB
,@@read_buffer_size  / (1024 * 1024 ) as read_buffer_size_MB
,@@read_rnd_buffer_size / (1024 * 1024 ) as read_rnd_buffer_size_MB
,@@sort_buffer_size  / (1024 * 1024 ) as sort_buffer_size_MB
,@@join_buffer_size  / (1024 * 1024 ) as join_buffer_size_MB
,@@binlog_cache_size / (1024 * 1024 ) as binlog_cache_size_MB
,@@thread_stack      /(1024 * 1024 ) as thread_stack_MB \G

结果:
*************************** 1. row ***************************
             MAX_MEMORY_GB: 1511.0586
innodb_buffer_pool_size_GB: 32.0000
           max_connections: 20000
            session_all_MB: 75.6250
         tmp_table_size_MB: 64.0000
       read_buffer_size_MB: 1.0000
   read_rnd_buffer_size_MB: 2.0000
       sort_buffer_size_MB: 8.0000
       join_buffer_size_MB: 0.1250
      binlog_cache_size_MB: 0.2500
           thread_stack_MB: 0.2500
1 row in set (0.00 sec)