The Performance Schema Memory-Allocation Model • Performance_schema_statement_classes_lost • Performance_schema_table_handles_lost • Performance_schema_table_instances_lost • Performance_schema_table_lock_stat_lost • Performance_schema_thread_classes_lost • Performance_schema_thread_instances_lost • Performance_schema_users_lost •May allocate memory at server startup •May allocate additional memory during server operation •Never free memory during server operation (although it might be recycled) •Free all memory used at shutdown The result is to relax memory constraints so that the Performance Schema can be used with less configuration, and to decrease the memory footprint so that consumption scales with server load. Memory used depends on the load actually seen, not the load estimated or explicitly configured for. Several Performance Schema sizing parameters are autoscaled and need not be configured explicitly unless you want to establish an explicit limit on memory allocation: performance_schema_accounts_size performance_schema_hosts_size performance_schema_max_cond_instances performance_schema_max_file_instances performance_schema_max_index_stat performance_schema_max_metadata_locks performance_schema_max_mutex_instances performance_schema_max_prepared_statements_instances performance_schema_max_program_instances 5122 How many statement instruments could not be loaded. How many table instrument instances could not be opened. This can be nonzero if the value of performance_schema_max_table_handles  is too small. How many table instrument instances could not be created. The number of tables for which lock statistics were lost. This can be nonzero if the value of performance_schema_max_table_lock_stat  is too small. How many thread instruments could not be loaded. The number of thread instances that could not be instrumented in the  threads  table. This can be nonzero if the value of  performance_schema_max_thread_instances  is too small. The number of times a row could not be added to the  users  table because it was full. The Performance Schema uses this memory allocation model: 27.17 The Performance Schema Memory-Allocation Model