MySQL内存消耗计算

mysql内存计算公式

mysql used mem=key_buffer_size+query_cache_size+tmp_table_size+innodb_buffer_pool_size
+innodb_additional_mem_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)

在mysql 中输入如下命令，可自动计算自己的当前配置最大的内存消耗

SHOW VARIABLES LIKE 'innodb_buffer_pool_size';
SHOW VARIABLES LIKE 'innodb_additional_mem_pool_size';
SHOW VARIABLES LIKE 'innodb_log_buffer_size';
SHOW VARIABLES LIKE 'thread_stack';
SET @kilo_bytes = 1024;
SET @mega_bytes = @kilo_bytes * 1024;
SET @giga_bytes =@mega_bytes * 1024;
SET @innodb_buffer_pool_size = 2 *@giga_bytes;
SET @innodb_additional_mem_pool_size = 16 *@mega_bytes;
SET @innodb_log_buffer_size = 8 *@mega_bytes;
SET @thread_stack = 192 *@kilo_bytes;

SELECT
    (
        @@key_buffer_size +@@query_cache_size +@@tmp_table_size +@innodb_buffer_pool_size +@innodb_additional_mem_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
        )
    ) /@giga_bytes AS MAX_MEMORY_GB

在mysql 中输入如下命令，可显示各占内存参数大小

SHOW VARIABLES LIKE 'key_buffer_size';
SHOW VARIABLES LIKE 'query_cache_size';
SHOW VARIABLES LIKE 'tmp_table_size';
SHOW VARIABLES LIKE 'innodb_buffer_pool_size';
SHOW VARIABLES LIKE 'innodb_additional_mem_pool_size';
SHOW VARIABLES LIKE 'innodb_log_buffer_size';
SHOW VARIABLES LIKE 'read_buffer_size';
SHOW VARIABLES LIKE 'read_rnd_buffer_size';
SHOW VARIABLES LIKE 'sort_buffer_size';
SHOW VARIABLES LIKE 'join_buffer_size';
SHOW VARIABLES LIKE 'binlog_cache_size';
SHOW VARIABLES LIKE 'thread_stack';