Optimize post insert and delete for bulk operations?

Question

Not much noticeable when working with individual posts, but when you create or delete multiple thousands in bulk and by code - process is quite slow.

Are there any good tweaks to apply and corners to cut?

Context:

• wp_insert_post() with categories and tags passed;
• add several custom fields;
• create and associate attachments (from existing files).

Answer 1

When updating post taxonomies, you can call wp_defer_term_counting( true ) before you do your mass operation, and then wp_defer_term_counting( false ) to update the term counts only once per term.