title: MySQL - Issue with Key Efficiency 100%
body: <p>I'm using MySQL Administrator tool to monitor the health of MySQL server. Whenever I run a lengthy JOIN query, I realized the Key Efficiency Graph shots up to 100% all the time. I do some read up and found out that the higher the Key Efficiency, mean the index cache is fully utilized.</p>
  
  <p>The problem is when Key Efficiency hits 100%, my other queries will run very slow or seems cannot run at all.</p>
  
  <p>These are my buffer settings. I'm using mostly InnoDB. MySQL version 5.0.77.</p>
  
  <pre>
  | bdb_log_buffer_size           | 262144     |
  | bulk_insert_buffer_size       | 8388608    |
  | innodb_buffer_pool_awe_mem_mb | 0          |
  | innodb_buffer_pool_size       | 1073741824 |
  | innodb_log_buffer_size        | 1048576    |
  | join_buffer_size              | 20971520   |
  | key_buffer_size               | 1073741824 |
  | myisam_sort_buffer_size       | 33554432   |
  | net_buffer_length             | 16384      |
  | preload_buffer_size           | 32768      |
  | read_buffer_size              | 20971520   |
  | read_rnd_buffer_size          | 4194304    |
  | sort_buffer_size              | 20971520   |
  </pre>