From a63e490a1eb8c5c2e7c6fbe978f82bfac57753df Mon Sep 17 00:00:00 2001
From: Jake Spurlock <whyisjake@git.wordpress.org>
Date: Thu, 19 Sep 2019 22:06:41 +0000
Subject: [PATCH] Multisite: Remove the redundant `blog_versions` table.

As part of the Multisite installation process, a `blog_versions` table is created. This table is never read from (except immediately prior to updating it), it's only ever inserted into or updated. It is not used to determine which blogs need to be upgraded.
This table was introduced in 3.0 when the WPMU schema was merged #11644 and it appears the table has never been used in core and is therefore redundant and may as well be removed.

Props johnbillion, nacin, ryan, johnjamesjacoby, whyisjake.

Fixes #19755. See #41685.



git-svn-id: https://develop.svn.wordpress.org/trunk@46194 602fd350-edb4-49c9-b593-d223f7449a82
---
 src/wp-admin/includes/schema.php  | 7 -------
 src/wp-admin/includes/upgrade.php | 7 -------
 src/wp-includes/wp-db.php         | 9 ---------
 3 files changed, 23 deletions(-)

diff --git a/src/wp-admin/includes/schema.php b/src/wp-admin/includes/schema.php
index dca64b3471..a2e8216457 100644
--- a/src/wp-admin/includes/schema.php
+++ b/src/wp-admin/includes/schema.php
@@ -261,13 +261,6 @@ CREATE TABLE $wpdb->posts (
 	KEY domain (domain(50),path(5)),
 	KEY lang_id (lang_id)
 ) $charset_collate;
-CREATE TABLE $wpdb->blog_versions (
-	blog_id bigint(20) NOT NULL default '0',
-	db_version varchar(20) NOT NULL default '',
-	last_updated datetime NOT NULL default '0000-00-00 00:00:00',
-	PRIMARY KEY  (blog_id),
-	KEY db_version (db_version)
-) $charset_collate;
 CREATE TABLE $wpdb->blogmeta (
 	meta_id bigint(20) unsigned NOT NULL auto_increment,
 	blog_id bigint(20) NOT NULL default '0',
diff --git a/src/wp-admin/includes/upgrade.php b/src/wp-admin/includes/upgrade.php
index d42673f01a..5aa0f12882 100644
--- a/src/wp-admin/includes/upgrade.php
+++ b/src/wp-admin/includes/upgrade.php
@@ -650,13 +650,6 @@ if ( ! function_exists( 'wp_upgrade' ) ) :
 		wp_cache_flush();
 
 		if ( is_multisite() ) {
-			$site_id = get_current_blog_id();
-
-			if ( $wpdb->get_row( $wpdb->prepare( "SELECT blog_id FROM {$wpdb->blog_versions} WHERE blog_id = %d", $site_id ) ) ) {
-				$wpdb->query( $wpdb->prepare( "UPDATE {$wpdb->blog_versions} SET db_version = %d WHERE blog_id = %d", $wp_db_version, $site_id ) );
-			} else {
-				$wpdb->query( $wpdb->prepare( "INSERT INTO {$wpdb->blog_versions} ( `blog_id` , `db_version` , `last_updated` ) VALUES ( %d, %d, NOW() );", $site_id, $wp_db_version ) );
-			}
 			update_site_meta( get_current_blog_id(), 'db_version', $wp_db_version );
 			update_site_meta( get_current_blog_id(), 'db_last_updated', microtime() );
 		}
diff --git a/src/wp-includes/wp-db.php b/src/wp-includes/wp-db.php
index 00f231a303..57471dc2ed 100644
--- a/src/wp-includes/wp-db.php
+++ b/src/wp-includes/wp-db.php
@@ -306,7 +306,6 @@ class wpdb {
 		'sitemeta',
 		'sitecategories',
 		'registration_log',
-		'blog_versions',
 	);
 
 	/**
@@ -425,14 +424,6 @@ class wpdb {
 	 */
 	public $blogmeta;
 
-	/**
-	 * Multisite Blog Versions table
-	 *
-	 * @since 3.0.0
-	 * @var string
-	 */
-	public $blog_versions;
-
 	/**
 	 * Multisite Registration Log table
 	 *