Server System Variables Defines a limit for the number of stored program definition objects, both used and unused, that can be kept in the dictionary object cache. Unused stored program definition objects are only kept in the dictionary object cache when the number in use is less than the capacity defined by  stored_program_definition_cache . A setting of 0 means that stored program definition objects are only kept in the dictionary object cache while they are in use. The stored program definition cache partition exists in parallel with the stored procedure and stored function caches that are configured using the  stored_program_cache  option. The  stored_program_cache  option sets a soft upper limit for the number of cached stored procedures or functions per connection, and the limit is checked each time a connection executes a stored procedure or function. The stored program definition cache partition, on the other hand, is a shared cache that stores stored program definition objects for other purposes. The existence of objects in the stored program definition cache partition has no dependence on the existence of objects in the stored procedure cache or stored function cache, and vice versa. For related information, see Section 14.4, “Dictionary Object Cache” . If the  read_only  system variable is enabled, the server permits no client updates except from users who have the  CONNECTION_ADMIN  privilege (or the deprecated  SUPER  privilege). If the super_read_only  system variable is also enabled, the server prohibits client updates even from users who have  CONNECTION_ADMIN  or  SUPER . See the description of the  read_only  system variable for a description of read-only mode and information about how  read_only  and  super_read_only  interact. Client updates prevented when  super_read_only  is enabled include operations that do not necessarily appear to be updates, such as  CREATE FUNCTION  (to install a loadable function),  INSTALL PLUGIN , and  INSTALL COMPONENT . These operations are prohibited because they involve changes to tables in the  mysql  system schema. Changes to  super_read_only  on a replication source server are not replicated to replica servers. The value can be set on a replica independent of the setting on the source. 895 • super_read_only Type Integer Default Value 256 Minimum Value 256 Maximum Value 524288 Command-Line Format --super-read-only[={OFF|ON}] System Variable super_read_only Scope Global Dynamic Yes SET_VAR  Hint Applies No Type Boolean Default Value OFF