Se você for armazenar todos os seus dados na memória, você também pode considerar usar um "banco de dados" de memória como Redis ou VoltDB.
Como posso evitar que o MYSQL grave no disco?
1
Estou usando o MEMORY Engine para todas as tabelas associadas a uma consulta MYSQL em particular, porque a velocidade de acesso é fundamental para o meu projeto.
Por algum motivo, notei que uma grande quantidade de E / S de disco ainda ocorre!
IssoocorreporqueoWindowsestátrocandoaRAMpelodisco?Comopossoevitarqueissoaconteça?
Edit:aquiestãominhasvariáveisglobais:
mysql>showglobalvariables;+---------------------------------------------------+--------------------------------------------------------------------------------------------------------------+|Variable_name|Value|+---------------------------------------------------+--------------------------------------------------------------------------------------------------------------+|auto_increment_increment|1||auto_increment_offset|1||autocommit|ON||automatic_sp_privileges|ON||back_log|50||basedir|C:/ProgramFiles/MySQL/MySQLServer5.5/||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:\ProgramFiles\MySQL\MySQLServer5.5\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\MySQLServer5.5\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
|
| sort_buffer_size | 32768
|
| sql_auto_is_null | OFF
|
| sql_big_selects | ON
|
| sql_big_tables | OFF
|
| sql_buffer_result | OFF
|
| sql_log_bin | OFF
|
| sql_log_off | OFF
|
| sql_low_priority_updates | OFF
|
| sql_max_join_size | 18446744073709551615
|
| sql_mode | STRICT_TRANS_TABLES,NO_AUTO_CREATE_USER,NO_ENGINE_SUBSTITUTION
|
| sql_notes | ON
|
| sql_quote_show_create | ON
|
| sql_safe_updates | OFF
|
| sql_select_limit | 18446744073709551615
|
| sql_slave_skip_counter | 0
|
| sql_warnings | OFF
|
| ssl_ca |
|
| ssl_capath |
|
| ssl_cert |
|
| ssl_cipher |
|
| ssl_key |
|
| storage_engine | MyISAM
|
| sync_binlog | 0
|
| sync_frm | ON
|
| sync_master_info | 0
|
| sync_relay_log | 0
|
| sync_relay_log_info | 0
|
| system_time_zone | Eastern Daylight Time
|
| table_definition_cache | 400
|
| table_open_cache | 128
|
| thread_cache_size | 0
|
| thread_concurrency | 10
|
| thread_handling | one-thread-per-connection
|
| thread_stack | 262144
|
| time_format | %H:%i:%s
|
| time_zone | SYSTEM
|
| timed_mutexes | OFF
|
| tmp_table_size | 134217728
|
| tmpdir | C:\Windows\TEMP
|
| transaction_alloc_block_size | 8192
|
| transaction_prealloc_size | 4096
|
| tx_isolation | REPEATABLE-READ
|
| unique_checks | ON
|
| updatable_views_with_limit | YES
|
| version | 5.5.11
|
| version_comment | MySQL Community Server (GPL)
|
| version_compile_machine | x86
|
| version_compile_os | Win64
|
| wait_timeout | 28800
|
+---------------------------------------------------+--------------------------------------------------------------------------------
por Mike Furlender
22.05.2011 / 02:26
3 respostas
1
por
22.05.2011 / 06:08
0
O link a seguir pode lançar alguma luz sobre o seu problema: link
If an internal temporary table is created initially as an in-memory table but becomes too large, MySQL automatically converts it to an on-disk table. The maximum size for in-memory temporary tables is the minimum of the tmp_table_size and max_heap_table_size values....
por
22.05.2011 / 05:47
0
Se você precisar de um armazenamento de memória, suponho que não seja necessário persistir os valores (caso contrário, não seria sensato usar uma tabela de memória). Se esse for o caso, você pode usar um dos "bancos de dados" sugeridos por Joshua ou usar o memcached , que é bastante rápido.
por
22.05.2011 / 06:17