Write me an SQL query snippet

I am looking for someone that can write an SQL Query snippet for me, which will delete all orphaned post meta tables in the database. It will be similar to this: DELETE pm FROM wp_postmeta pm LEFT JOIN wp_posts wp ON [login to view URL] = pm.post_id WHERE [login to view URL] IS NULL However, I need the data deleted in batches of 100,000 - because there are over a million rows of orphaned data and it keeps timing out on me.