Fat wp_postmeta table needs liposuction

I'm a terrible website owner.

I have let my database get WAY out of control. My wp_postmeta table has grown to over 250 million rows (around 30GB) - most of which is orphaned.

Yes, you read that right.

I've tried using phpmyadmin to run queries to clean up some orphaned post meta - but it keeps timing out.

I basically need an experienced database administrator to spend some time going through my postmeta table and help shrink it down.

I do have some other tasks I would like to chat about, along the same lines - but nothing can be done until we get this table trimmed.

Is there a doctor in the building?