Could

Can I split a huge wp_postmeta table across different databases or servers?

Can I split a huge wp_postmeta table across different databases or servers?

No. This is not practically possible primarily because there is no single interface to this table where you could implement the functionality you need, and even if you could, it would introduce some extremely gnarly problems.

Wordpress Permalink Issue for media permalink leading to 404 page when set as postname
How do I fix a permalink issue in WordPress? How do I change the media Permalink in WordPress? How do I change permalinks in WordPress without breakin...
Remove /category/ from category (archive) page URLs (without using a plugin)
How do I remove category names from URL? How do I remove category categories from WordPress URL? How do I remove a product category base? How do I rem...
Add sync-able bookings calendar to the site [closed]
How do I sync my booking calendar? How do I sync my Outlook calendar with bookings? Can you sync booking com and Airbnb calendars? Does Microsoft book...