In my previous post I took you through all the tables of the WordPress database for a single site install. In this tour I will be looking at the tables and database changes for a Multisite installation of WordPress. When a WordPress site is converted to a Multisite install, a “network” of subsites is created. The existing site is converted to the first subsite in the network. The database classes the network itself as a site (wp_site), and each subsite as a blog (wp_blogs). Certain tables are used only by a subsite, and a new set of tables are created every time a site is added to the network. Each set of tables is differentiated by the blog_id for the subsite used in the table prefix. e.g.
wp_2_posts. The following tables are subsite specific: The wp_users and wp_usermeta tables become global across the subsites in the network, and during the network installation a couple of extra columns are added to the wp_users table: spam – mark as a spam user. deleted – mark as a deleted user. Multisite Only Tables The following tables are created during the network installation to help manage the network: wp_site This table will contain the one network for the installation although the table