MySQL 5.7 和 MySQL 5.6引數預設值比較
這裡只拿出預設值有改變的引數，預設值沒有改變的不在下面的列表中。這些資料是通過 ” show global variables ;” 獲得，可能不是所有的引數。
| 引數 |
MySQL 5.6 |
MySQL 5.7 |
| binlog_error_action |
IGNORE_ERROR |
ABORT_SERVER |
| binlog_format |
STATEMENT |
ROW |
| binlog_gtid_simple_recovery |
OFF |
ON |
| eq_range_index_dive_limit |
10 |
200 |
| innodb_buffer_pool_dump_at_shutdown |
OFF |
ON |
| innodb_buffer_pool_instances |
8 |
1 |
| innodb_buffer_pool_load_at_startup |
OFF |
ON |
| innodb_checksum_algorithm |
innodb |
crc32 |
| innodb_file_format |
Antelope |
Barracuda |
| innodb_file_format_max |
Antelope |
Barracuda |
| innodb_large_prefix |
OFF |
ON |
| innodb_log_buffer_size |
8388608 |
16777216 |
| innodb_purge_threads |
1 |
4 |
| innodb_strict_mode |
OFF |
ON |
| innodb_use_native_aio |
ON |
OFF |
| log_warnings |
1 |
2 |
| optimizer_switch |
index_merge=on,index_merge_union=on,index_merge_sort_union=on, index_merge_intersection=on,engine_condition_pushdown=on, index_condition_pushdown=on,mrr=on,mrr_cost_based=on, block_nested_loop=on,batched_key_access=off,materialization=on, semijoin=on,loosescan=on,firstmatch=on, subquery_materialization_cost_based=on,use_index_extensions=on |
index_merge=on,index_merge_union=on,index_merge_sort_union=on, index_merge_intersection=on,engine_condition_pushdown=on, index_condition_pushdown=on,mrr=on,mrr_cost_based=on, block_nested_loop=on,batched_key_access=off,materialization=on, semijoin=on,loosescan=on,firstmatch=on,duplicateweedout=on, subquery_materialization_cost_based=on,use_index_extensions=on, condition_fanout_filter=on,derived_merge=on |
| performance_schema_accounts_size |
100 |
-1 |
| performance_schema_max_cond_instances |
3504 |
-1 |
| performance_schema_max_file_classes |
50 |
80 |
| performance_schema_max_file_instances |
7693 |
-1 |
| performance_schema_max_mutex_classes |
200 |
210 |
| performance_schema_max_mutex_instances |
15906 |
-1 |
| performance_schema_max_rwlock_instances |
9102 |
-1 |
| performance_schema_max_socket_instances |
322 |
-1 |
| performance_schema_max_statement_classes |
168 |
193 |
| performance_schema_max_table_handles |
4000 |
-1 |
| performance_schema_max_table_instances |
12500 |
-1 |
| performance_schema_max_thread_instances |
402 |
-1 |
| performance_schema_setup_actors_size |
100 |
-1 |
| performance_schema_setup_objects_size |
100 |
-1 |
| performance_schema_users_size |
100 |
-1 |
| slave_net_timeout |
3600 |
60 |
| sql_mode |
STRICT_TRANS_TABLES,NO_ENGINE_SUBSTITUTION |
ONLY_FULL_GROUP_BY,STRICT_TRANS_TABLES,NO_ZERO_IN_DATE, NO_ZERO_DATE,ERROR_FOR_DIVISION_BY_ZERO, NO_AUTO_CREATE_USER,NO_ENGINE_SUBSTITUTION |
| sync_binlog |
0 |
1 |
| table_open_cache_instances |
1 |
16 |
- binlog_format
binlog的格式預設為ROW，在mysql5.6時binlog的格式為STATEMENT。
- innodb_buffer_pool_instances
Buffer pool 的數量，預設值為1，在MySQL5.6該值為8。
- innodb_checksum_algorithm
指定如何生成和驗證儲存在InnoDB表空間的磁碟塊中的校驗和。預設值使用效能更好的crc32 。
- innodb_log_buffer_size
innodb重做日誌緩衝空間預設為16M,在 MySQL 5.6時這個值為8M。
- innodb_purge_threads
Purge執行緒的數量預設為4，在MySQL5.6時預設值為1。
- sql_mode
預設sql mode 增加了ONLY_FULL_GROUP_BY、ERROR_FOR_DIVISION_BY_ZERO、 NO_ZERO_DATE、 NO_ZERO_IN_DATE 等。
- sync_binlog
預設值為1，表示binlog日誌同步寫入磁碟。MySQL 5.6該引數預設值為0。