Rational configuration of MySQL Open_Table

MySQL Opened_tables indicates the number of opened tables. The following describes how to reasonably configure the value of MySQL Open_Table. It is helpful for you to learn about MySQL databases.

MySQL Open_Table:

 
 

  
  
mysql> show global status like 'open%tables%';  
  
  
+---------------+-------+  
  
  
| Variable_name | Value |  
  
  
+---------------+-------+  
  
  
| Open_tables | 919 |  
  
  
| Opened_tables | 1951 |  
  
  
+---------------+-------+ 
 
 

MySQL Open_tables indicates the number of opened tables. If the number of MySQL Opened_tables is too large, the value of table_cache in the configuration may be too small (table_open_cache after 5.1.3). Let's query the value of table_cache on the server:

 
 

  
  
mysql> show variables like 'table_cache';  
  
  
+---------------+-------+  
  
  
| Variable_name | Value |  
  
  
+---------------+-------+  
  
  
| table_cache | 2048 |  
  
  
+---------------+-------+ 
 
 

MySQL Open_Table has the following values:

 
 

  
  
Open_tables / Opened_tables * 100% >= 85%  
  
  
Open_tables / table_cache * 100%  
 
 

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