Estoy usando MEMORY Enginepara todas las tablas asociadas con una consulta MYSQL particular porque la velocidad de acceso es primordial para mi proyecto.
Por alguna razón, he notado que todavía se produce una gran cantidad de escritura en disco.
¿Esto se debe a que Windows cambió la RAM al disco? ¿Cómo puedo evitar que esto suceda?
Editar: Aquí están mis variables globales:
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
|
| 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
|
+---------------------------------------------------+--------------------------------------------------------------------------------
mysql
memory
storage-engine
Mike Furlender
fuente
fuente
Respuestas:
Es posible que desee ver cuántas tablas de MEMORIA está utilizando. Incluso con una tabla MEMORY, debe haber un identificador de archivo abierto para el archivo .frm de la tabla MEMORY. Verifique su límite de archivos abiertos. Es posible que necesite aumentar eso también.
También tiene una gran disparidad entre read_buffer_size y read_rnd_buffer_size.
Tiene read_buffer_size a 64M y read_rnd_buffer_size a 4M.
Nunca he visto una configuración con read_buffer_size mucho más grande que read_rnd_buffer_size
Debe hacerlo de la siguiente manera:
Estas cosas contribuyen a leer E / S, no a escribir E / S.
Aquí hay algo a considerar:
¿Tienes otras tablas usando MyISAM?
¿Ejecutas consultas JOIN que mezclan tablas MEMORY y tablas MyISAM?
¿Las tablas temporales exceden los 128M ?
fuente
La escritura de E / S fue el resultado de repetidas declaraciones
DROP TABLE/CREATE TABLE. Los reemplacé conTRUNCATE TABLEy el problema se ha ido.fuente
Creo que es hora de hacer algunas matemáticas. ¿Cuál es su memoria RAM del sistema frente al tamaño de la mesa que está tratando de meter? ¿Cuál es el tamaño de la estructura (requisitos de almacenamiento de datos de cada fila) que está almacenando en su tabla de memoria?
¿Has multiplicado esas filas * qty para ver si eso excede tus valores?
http://dev.mysql.com/doc/refman/5.0/en/memory-storage-engine.html
Otros pensamientos: ¿Sus límites para tmp_table_size y max_heap_table_size son 128M, pero su key_buffer es 24M? Impar. Además, sus búferes de unión y clasificación parecen ser bastante pequeños. Experimentaría elevando tu key_buffer a 128M.
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