can't set batched_key_access=on in optimizer_switch on mariadb 5.5 I am switching my application from a Mysql5.6 to a Mariadb5.5. I am support to add batched_key_access=on in optimizer_switch, but when I do that, mariadb refuse to start :

170104 17:16:14 mysqld_safe mysqld from pid file /var/run/mysqld/mysqld.pid ended
170104 17:16:25 mysqld_safe Starting mysqld daemon with databases from /data/mysqldata
170104 17:16:26 [ERROR] /data/mysql/bin/mysqld: Error while setting value 'batched_key_access=off' to 'optimizer_switch'
170104 17:16:26 [ERROR] Aborting


When I read Mariadb Docs, I am supposer to set mrr=on which is what I do :

optimizer_switch='index_condition_pushdown=off'
optimizer_switch='mrr=on'
optimizer_switch='mrr_cost_based=off'
optimizer_switch='batched_key_access=on'


Am I doing something wrong?

Thank you for your help.
There is no batched_key_access key in MariaDB -- the functionality was released in MariaDB 5.3, long before MySQL 5.6, so it naturally had its own naming, from which MySQL diverged. What you might be looking for is join_cache_bka, but please read the page about block-based algorithms in full, as you also need to choose a suitable value for join_cache_level, depending on your needs.