I have a table with the following columns:
URL_ID URL_ADDR URL_Time
I want to remove duplicates on the URL_ADDR column
URL_ADDR
You may want to try the method mentioned at http://labs.creativecommons.org/2010/01/12/removing-duplicate-rows-in-mysql/.
ALTER IGNORE TABLE your_table ADD UNIQUE INDEX `tmp_index` (URL_ADDR);