我们可以在创建表/索引时设置一个新变量,即MERGE_THRESHOLD。
其描述在这里: Merge threshold for innodb index pages
但是如何检查merge_threshold的当前值呢?
我像检查其他变量一样使用了这个查询,但没有成功。
show variables like 'MERGE_THRESHOLD' ;
最佳答案
答案可以在您的 MySQL 文档中找到 linked in your question :
The current MERGE_THRESHOLD value for an index can be obtained by querying the INNODB_SYS_INDEXES table. For example:
mysql> SELECT * FROM INFORMATION_SCHEMA.INNODB_SYS_INDEXES WHERE NAME='id_index' \G *************************** 1. row *************************** INDEX_ID: 91 NAME: id_index TABLE_ID: 68 TYPE: 0 N_FIELDS: 1 PAGE_NO: 4 SPACE: 57 MERGE_THRESHOLD: 40
You can use SHOW CREATE TABLE to view the MERGE_THRESHOLD value for a table, if explicitly defined using the table_option COMMENT clause:
mysql> SHOW CREATE TABLE t2 \G *************************** 1. row *************************** Table: t2 Create Table: CREATE TABLE `t2` ( `id` int(11) DEFAULT NULL, KEY `id_index` (`id`) COMMENT 'MERGE_THRESHOLD=40' ) ENGINE=InnoDB DEFAULT CHARSET=latin1
关于mysql - 如何检查MySQL中当前的MERGE_THRESHOLD值?,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/38263608/