#MariaDB #Memory Allocation - MariaDB Knowledge Base
Allocating RAM for MySQL - The short answer
If using just MyISAM, set key_buffer_size to 20% of available RAM. (Plus innodb_buffer_pool_size=0)
If using just InnoDB, set innodb_buffer_pool_size to 70% of available RAM. (Plus key_buffer_size = 10M, small, but not zero.)
Rule of thumb for tuning mysql:
– Start with released copy of my.cnf / my.ini.
– Change key_buffer_size and innodb_buffer_pool_size according to engine usage and RAM.
– Slow queries can usually be ’fixed’ via indexes, schema changes, or SELECT changes, not by tuning.
– Don’t get carried away with the query cache until you understand what it can and cannot do.
– Don’t change anything else unless you run into trouble (eg, max connections).
– Be sure the changes are under the [mysqld] section, not some other section.
The 20%/70% assumes you have at least 4GB of RAM. If you have a tiny antique, or a tiny VM, then those percentages are too high.
Now for the gory details. (NDB Cluster is not discussed here.)