title: Drop Column from Large Table
body: <p>I have this largish table with three columns as such:</p>
  
  <pre><code>+-----+-----+----------+
  | id1 | id2 | associd  |
  +-----+-----+----------+
  |   1 |  38 | 73157604 |
  |   1 | 112 | 73157605 |
  |   1 | 113 | 73157606 |
  |   1 | 198 | 31936810 |
  |   1 | 391 | 73157607 |
  +-----+-----+----------+
  </code></pre>
  
  <p>This continues for 38m rows. The problem is I want to remove the 'associd' column but running <code>ALTER TABLE table_name DROP COLUMN associd;</code> simply takes too long. I wanted to do something like: <code>ALTER TABLE table_name SET UNUSED associd;</code> and <code>ALTER TABLE table_name DROP UNUSED COLUMNS CHECKPOINT 250;</code> then which apparently speeds up the process but <a href="http://forums.phpfreaks.com/topic/115428-solved-set-unused-column-for-mysql/" rel="noreferrer">it isn't possible in MySQL?</a></p>
  
  <p>Is there an alternative to remove this column-- maybe creating a new table with only the two columns or getting a drop with checkpoints?</p>