InnoDB-related setting Variables

| Innodb_adaptive_hash_index | on | whether to enable adaptive hash Indexes
| Innodb_additional_mem_pool_size | 1048576 | size of the memory pool in which InnoDB stores data directory information and other internal data structures
| Innodb_autoextend_increment | 8 | size (MB) added for expansion when the auto-extended tablespace is filled)
| Innodb_autoinc_lock_mode | 1 | the locking mode to use for generating auto-increment values, the allowable values are 0, 1, or 2, for "traditional", "consecutive ", or "interleaved" lock mode
| Innodb_buffer_pool_size | 8388608 | buffer pool size
| Innodb_checksums | on | InnoDB uses checksum verification on all disk page reads to ensure extra fault tolerance to prevent hardware corruption or data files
| Innodb_commit_concurrency | 0 | the number of threads that can commit at the same time
| Innodb_concurrency_tickets | 500 | check is not required until the thread has exhausted this value and enters InnoDB again.
| Innodb_data_file_path | ibdata1: 10 m: autoextend | InnoDB Data File
| Innodb_data_home_dir | InnoDB file directory
| Innodb_doublewrite | on | InnoDB stores all data twice, dual-write
| Innodb_fast_shutdown | 1 | type of operation InnoDB performs when it is disabled
| Innodb_file_io_threads | 4 | Number of file I/O threads in InnoDB
| Innodb_file_per_table | off | InnoDB uses its own. IBD file to create a new table for storing data and indexes, instead of creating a new table in the shared tablespace.
| Innodb_flush_log_at_trx_commit | 1 |, 2 log buffering-> log file-> disk refresh time
| Innodb_flush_method | used to flush
| Innodb_force_recovery | 0 | 1-6 when the value of this option is greater than zero, InnoDB prevents users from modifying data.
| Innodb_lock_wait_timeout | 50 | InnoDB transactions can wait for a locked timeout period before being rolled back.
| Innodb_locks_unsafe_for_binlog | off | index lock + gap lock (phantom read)
| Innodb_log_buffer_size | 1048576 | size of the buffer used by InnoDB to write log files from and to the disk
| Innodb_log_file_size | 5242880 | size of each log file in the log Group
| Innodb_log_files_in_group | 2 | Number of log files in the log Group
| Innodb_log_group_home_dir |./| directory path to the InnoDB Log File
| Innodb_max_dirty_pages_pct | 90 | the main thread in InnoDB tries to write pages from the buffer pool so that the percentage of dirty pages (unwritten pages) cannot exceed this value.
| Innodb_max_purge_lag | 0 | this option controls how to delay insert, update, and delete operations when the purification operation is delayed. The default value of this parameter is zero, meaning that the InnoDB Transaction System maintains a transaction list without delay. This list contains the index records marked as deleted by the update or delete operation. Set the list length to purge_lag. When purge_lag exceeds innodb_max_purge_lag, each insert, update, and delete operation delay (purge_lag/innodb_max_purge_lag) * 10)-5 milliseconds
| Innodb_mirrored_log_groups | 1 | the same number of copies in the log group that we keep for the database
| Innodb_open_files | 300 | in InnoDB, this option is only related to your use of multiple tablespaces. It specifies the maximum number of. IBD files that InnoDB can open at a time.
| Snapshot | off | InnoDB rolls back only the last statement on a transaction timeout by default. If -- innodb_rollback_on_timeout is specified, a transaction timeout causes InnoDB to abort and roll back the entire transaction
| Innodb_stats_on_metadata | on | when this variable is enabled (which is the default, as before the variable was created), InnoDB updates statistics during metadata statements such as show table status or show index, or when accessing the information_schema tables or statistics
| Innodb_support_xa | on | InnoDB support for two-phase commit in XA transactions is enabled
| Innodb_sync_spin_loops | 20 | the number of times a thread waits for an InnoDB mutex to be freed before the thread is suincluded
| Innodb_table_locks | on | InnoDB attaches importance to lock tables until all other threads have released all their table locks.
| Innodb_thread_concurrency | 8 | InnoDB tries to keep the number of operating system threads less than or equal to the limit given by this parameter
| Innodb_thread_sleep_delay | 10000 | how long InnoDB threads sleep before joining the InnoDB queue, in microseconds
| Innodb_use_legacy_cardinality_algorithm | on | whether the original random cardinality algorithm can be used