MySQL Memory Calculator

mysql_memory_calculator.md

MySQL 5.6

Base memory

SELECT ( @@key_buffer_size
+ @@query_cache_size
+ @@innodb_buffer_pool_size
+ @@innodb_log_buffer_size
+ @@innodb_additional_mem_pool_size )
/ (1024 * 1024 * 1024) AS BASE_MEMORY_GB;

Max memory

SELECT ( @@key_buffer_size
+ @@query_cache_size
+ @@innodb_buffer_pool_size
+ @@innodb_log_buffer_size
+ @@innodb_additional_mem_pool_size
+ @@max_connections * ( 
    @@read_buffer_size
    + @@read_rnd_buffer_size
    + @@sort_buffer_size
    + @@join_buffer_size
    + @@binlog_cache_size
    + @@thread_stack
    + @@max_heap_table_size )
) / (1024 * 1024 * 1024) AS MAX_MEMORY_GB;

MySQL 5.7

Base memory

SELECT ( @@key_buffer_size
+ @@query_cache_size
+ @@innodb_buffer_pool_size
+ @@innodb_log_buffer_size )
/ (1024 * 1024 * 1024) AS BASE_MEMORY_GB;

Max memory

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
    + @@max_heap_table_size )
) / (1024 * 1024 * 1024) AS MAX_MEMORY_GB;

MySQL 8.x

Base memory

SELECT ( @@key_buffer_size
+ @@query_cache_size
+ @@innodb_buffer_pool_size
+ @@innodb_log_buffer_size )
/ (1024 * 1024 * 1024) AS BASE_MEMORY_GB;

Max memory

SELECT ( @@key_buffer_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
    + @@max_heap_table_size )
) / (1024 * 1024 * 1024) AS MAX_MEMORY_GB;