Understanding Redundant postmeta Tables in WordPress Database

Question

I have noticed that my WordPress database contains three identical postmeta tables. Each of these tables seems to hold the same information.

Is it normal to have multiple postmeta tables in a WordPress database?

What could be the reason behind this duplication?

Can I safely delete two of these postmeta tables without affecting my WordPress site functionality or causing data loss?

I'd like to optimize my database and remove any unnecessary duplication, but I want to ensure I'm not disrupting the functionality of my site. Any insights or guidance on managing these redundant tables would be greatly appreciated.

Thanks in advance!

Answer 1

Is it normal to have multiple postmeta tables in a WordPress database?

No, each site has a single post/user/term and comment meta table.

A multisite will have a set of those tables for each site in the multisite, plus network/site meta tables.

What could be the reason behind this duplication?

WP wouldn't duplicate the tables like this. This is probably the work of a plugin, a bug, or a backup system you're unaware of.

It's also possible there are multiple copies of the site using the same database but with different prefixes. This might be the case if someone has set up a staging/dev environment, and would explain why the data appears to be the same.

Can I safely delete two of these postmeta tables without affecting my WordPress site functionality or causing data loss?

Unknown, and nobody on the internet can answer this question for you.

1. Take a backup
2. Delete the tables
3. Test everything and see what broke
   • if things broke restore backups