Mik*_*der 10 mysql storage-engine memory
我将MEMORY Engine用于与特定 MYSQL 查询关联的所有表，因为访问速度对我的项目至关重要。
出于某种原因，我注意到仍然会发生大量磁盘写入。
这是因为 Windows 将 RAM 交换到磁盘吗？我怎样才能防止这种情况发生？
编辑：这是我的全局变量：
mysql> show global variables;
+---------------------------------------------------+--------------------------------------------------------------------------------
------------------------------+
| Variable_name | Value
|
+---------------------------------------------------+--------------------------------------------------------------------------------
------------------------------+
| auto_increment_increment | 1
|
| auto_increment_offset | 1
|
| autocommit | ON
|
| automatic_sp_privileges | ON
|
| back_log | 50
|
| basedir | C:/Program Files/MySQL/MySQL Server 5.5/
|
| big_tables | OFF
|
| binlog_cache_size | 32768
|
| binlog_direct_non_transactional_updates | OFF
|
| binlog_format | STATEMENT
|
| binlog_stmt_cache_size | 4096
|
| bulk_insert_buffer_size | 8388608
|
| character_set_client | latin1
|
| character_set_connection | latin1
|
| character_set_database | latin1
|
| character_set_filesystem | binary
|
| character_set_results | latin1
|
| character_set_server | latin1
|
| character_set_system | utf8
|
| character_sets_dir | C:\Program Files\MySQL\MySQL Server 5.5\share\charsets\
|
| collation_connection | latin1_swedish_ci
|
| collation_database | latin1_swedish_ci
|
| collation_server | latin1_swedish_ci
|
| completion_type | NO_CHAIN
|
| concurrent_insert | AUTO
|
| connect_timeout | 10
|
| datadir | C:\ProgramData\MySQL\MySQL Server 5.5\Data\
|
| date_format | %Y-%m-%d
|
| datetime_format | %Y-%m-%d %H:%i:%s
|
| default_storage_engine | MyISAM
|
| default_week_format | 0
|
| delay_key_write | OFF
|
| delayed_insert_limit | 100
|
| delayed_insert_timeout | 300
|
| delayed_queue_size | 1000
|
| div_precision_increment | 4
|
| engine_condition_pushdown | ON
|
| event_scheduler | OFF
|
| expire_logs_days | 0
|
| flush | OFF
|
| flush_time | 1800
|
| foreign_key_checks | ON
|
| ft_boolean_syntax | + -><()~*:""&|
|
| ft_max_word_len | 84
|
| ft_min_word_len | 4
|
| ft_query_expansion_limit | 20
|
| ft_stopword_file | (built-in)
|
| general_log | OFF
|
| general_log_file | C:\ProgramData\MySQL\MySQL Server 5.5\Data\FXMachine.log
|
| group_concat_max_len | 1024
|
| have_compress | YES
|
| have_crypt | NO
|
| have_csv | YES
|
| have_dynamic_loading | YES
|
| have_geometry | YES
|
| have_innodb | DISABLED
|
| have_ndbcluster | NO
|
| have_openssl | DISABLED
|
| have_partitioning | YES
|
| have_profiling | YES
|
| have_query_cache | YES
|
| have_rtree_keys | YES
|
| have_ssl | DISABLED
|
| have_symlink | YES
|
| hostname | FXMachine
|
| ignore_builtin_innodb | OFF
|
| init_connect |
|
| init_file |
|
| init_slave |
|
| interactive_timeout | 28800
|
| join_buffer_size | 25600
|
| keep_files_on_create | OFF
|
| key_buffer_size | 25165824
|
| key_cache_age_threshold | 300
|
| key_cache_block_size | 1024
|
| key_cache_division_limit | 100
|
| large_files_support | ON
|
| large_page_size | 0
|
| large_pages | OFF
|
| lc_messages | en_US
|
| lc_messages_dir | C:\Program Files\MySQL\MySQL Server 5.5\share\
|
| lc_time_names | en_US
|
| license | GPL
|
| local_infile | ON
|
| lock_wait_timeout | 31536000
|
| log | OFF
|
| log_bin | OFF
|
| log_bin_trust_function_creators | OFF
|
| log_error | C:\ProgramData\MySQL\MySQL Server 5.5\Data\FXMachine.err
|
| log_output | FILE
|
| log_queries_not_using_indexes | OFF
|
| log_slave_updates | OFF
|
| log_slow_queries | OFF
|
| log_warnings | 1
|
| long_query_time | 10.000000
|
| low_priority_updates | OFF
|
| lower_case_file_system | ON
|
| lower_case_table_names | 1
|
| max_allowed_packet | 1048576
|
| max_binlog_cache_size | 4096
|
| max_binlog_size | 4096
|
| max_binlog_stmt_cache_size | 4096
|
| max_connect_errors | 10
|
| max_connections | 10
|
| max_delayed_threads | 20
|
| max_error_count | 64
|
| max_heap_table_size | 134217728
|
| max_insert_delayed_threads | 20
|
| max_join_size | 18446744073709551615
|
| max_length_for_sort_data | 1024
|
| max_long_data_size | 1048576
|
| max_prepared_stmt_count | 16382
|
| max_relay_log_size | 0
|
| max_seeks_for_key | 4294967295
|
| max_sort_length | 1024
|
| max_sp_recursion_depth | 0
|
| max_tmp_tables | 32
|
| max_user_connections | 0
|
| max_write_lock_count | 4294967295
|
| min_examined_row_limit | 0
|
| multi_range_count | 256
|
| myisam_data_pointer_size | 6
|
| myisam_max_sort_file_size | 2146435072
|
| myisam_mmap_size | 18446744073709551615
|
| myisam_recover_options | OFF
|
| myisam_repair_threads | 1
|
| myisam_sort_buffer_size | 8388608
|
| myisam_stats_method | nulls_unequal
|
| myisam_use_mmap | OFF
|
| named_pipe | ON
|
| net_buffer_length | 16384
|
| net_read_timeout | 30
|
| net_retry_count | 10
|
| net_write_timeout | 60
|
| new | OFF
|
| old | OFF
|
| old_alter_table | OFF
|
| old_passwords | OFF
|
| open_files_limit | 2324
|
| optimizer_prune_level | 1
|
| optimizer_search_depth | 62
|
| optimizer_switch | index_merge=on,index_merge_union=on,index_merge_sort_union=on,index_merge_inter
,engine_condition_pushdown=on |
| performance_schema | OFF
|
| performance_schema_events_waits_history_long_size | 10000
|
| performance_schema_events_waits_history_size | 10
|
| performance_schema_max_cond_classes | 80
|
| performance_schema_max_cond_instances | 1000
|
| performance_schema_max_file_classes | 50
|
| performance_schema_max_file_handles | 32768
|
| performance_schema_max_file_instances | 10000
|
| performance_schema_max_mutex_classes | 200
|
| performance_schema_max_mutex_instances | 1000000
|
| performance_schema_max_rwlock_classes | 30
|
| performance_schema_max_rwlock_instances | 1000000
|
| performance_schema_max_table_handles | 100000
|
| performance_schema_max_table_instances | 50000
|
| performance_schema_max_thread_classes | 50
|
| performance_schema_max_thread_instances | 1000
|
| pid_file | C:\ProgramData\MySQL\MySQL Server 5.5\Data\FXMachine.pid
|
| plugin_dir | C:\Program Files\MySQL\MySQL Server 5.5\lib/plugin
|
| port | 0
|
| preload_buffer_size | 32768
|
| profiling | OFF
|
| profiling_history_size | 15
|
| protocol_version | 10
|
| query_alloc_block_size | 8192
|
| query_cache_limit | 1048576
|
| query_cache_min_res_unit | 4096
|
| query_cache_size | 0
|
| query_cache_type | OFF
|
| query_cache_wlock_invalidate | OFF
|
| query_prealloc_size | 8192
|
| range_alloc_block_size | 4096
|
| read_buffer_size | 67108864
|
| read_only | OFF
|
| read_rnd_buffer_size | 4194304
|
| relay_log |
|
| relay_log_index |
|
| relay_log_info_file | relay-log.info
|
| relay_log_purge | ON
|
| relay_log_recovery | OFF
|
| relay_log_space_limit | 0
|
| report_host |
|
| report_password |
|
| report_port | 3306
|
| report_user |
|
| rpl_recovery_rank | 0
|
| secure_auth | OFF
|
| secure_file_priv |
|
| server_id | 0
|
| shared_memory | OFF
|
| shared_memory_base_name | MYSQL
|
| skip_external_locking | ON
|
| skip_name_resolve | OFF
|
| skip_networking | ON
|
| skip_show_database | OFF
|
| slave_compressed_protocol | OFF
|
| slave_exec_mode | STRICT
|
| slave_load_tmpdir | C:\Windows\TEMP
|
| slave_net_timeout | 3600
|
| slave_skip_errors | OFF
|
| slave_transaction_retries | 10
|
| slave_type_conversions |
|
| slow_launch_time | 2
|
| slow_query_log | OFF
|
| slow_query_log_file | C:\ProgramData\MySQL\MySQL Server 5.5\Data\FXMachine-slow.log
|
| socket | mysql
您可能想查看正在使用的 MEMORY 表的数量。即使有 MEMORY 表，也必须有一个 MEMORY 表的 .frm 的打开文件句柄。检查您的 open_files_limit。您可能还需要增加它。
read_buffer_size 和 read_rnd_buffer_size 之间也存在很大差异。
你有 64M 的 read_buffer_size 和 4M 的 read_rnd_buffer_size。
我从未见过 read_buffer_size 比 read_rnd_buffer_size 大得多的配置
你应该按如下方式进行：
read_buffer_size = 16M
read_rnd_buffer_size = 64M
这些东西有助于读 I/O，而不是写 I/O。
这里有一些事情需要考虑：
你有其他使用 MyISAM 的表吗？？？
您是否运行混合 MEMORY 表和 MyISAM 表的 JOIN 查询？？？