diff --git a/database.sql b/database.sql
index e2a0f243a..e2b333a6d 100644
--- a/database.sql
+++ b/database.sql
@@ -1,6 +1,6 @@
 -- ------------------------------------------
 -- Friendica 2020.12-dev (Red Hot Poker)
--- DB_UPDATE_VERSION 1372
+-- DB_UPDATE_VERSION 1376
 -- ------------------------------------------
 
 
@@ -33,6 +33,61 @@ CREATE TABLE IF NOT EXISTS `gserver` (
 	 UNIQUE INDEX `nurl` (`nurl`(190))
 ) DEFAULT COLLATE utf8mb4_general_ci COMMENT='Global servers';
 
+--
+-- TABLE user
+--
+CREATE TABLE IF NOT EXISTS `user` (
+	`uid` mediumint unsigned NOT NULL auto_increment COMMENT 'sequential ID',
+	`parent-uid` mediumint unsigned COMMENT 'The parent user that has full control about this user',
+	`guid` varchar(64) NOT NULL DEFAULT '' COMMENT 'A unique identifier for this user',
+	`username` varchar(255) NOT NULL DEFAULT '' COMMENT 'Name that this user is known by',
+	`password` varchar(255) NOT NULL DEFAULT '' COMMENT 'encrypted password',
+	`legacy_password` boolean NOT NULL DEFAULT '0' COMMENT 'Is the password hash double-hashed?',
+	`nickname` varchar(255) NOT NULL DEFAULT '' COMMENT 'nick- and user name',
+	`email` varchar(255) NOT NULL DEFAULT '' COMMENT 'the users email address',
+	`openid` varchar(255) NOT NULL DEFAULT '' COMMENT '',
+	`timezone` varchar(128) NOT NULL DEFAULT '' COMMENT 'PHP-legal timezone',
+	`language` varchar(32) NOT NULL DEFAULT 'en' COMMENT 'default language',
+	`register_date` datetime NOT NULL DEFAULT '0001-01-01 00:00:00' COMMENT 'timestamp of registration',
+	`login_date` datetime NOT NULL DEFAULT '0001-01-01 00:00:00' COMMENT 'timestamp of last login',
+	`default-location` varchar(255) NOT NULL DEFAULT '' COMMENT 'Default for item.location',
+	`allow_location` boolean NOT NULL DEFAULT '0' COMMENT '1 allows to display the location',
+	`theme` varchar(255) NOT NULL DEFAULT '' COMMENT 'user theme preference',
+	`pubkey` text COMMENT 'RSA public key 4096 bit',
+	`prvkey` text COMMENT 'RSA private key 4096 bit',
+	`spubkey` text COMMENT '',
+	`sprvkey` text COMMENT '',
+	`verified` boolean NOT NULL DEFAULT '0' COMMENT 'user is verified through email',
+	`blocked` boolean NOT NULL DEFAULT '0' COMMENT '1 for user is blocked',
+	`blockwall` boolean NOT NULL DEFAULT '0' COMMENT 'Prohibit contacts to post to the profile page of the user',
+	`hidewall` boolean NOT NULL DEFAULT '0' COMMENT 'Hide profile details from unkown viewers',
+	`blocktags` boolean NOT NULL DEFAULT '0' COMMENT 'Prohibit contacts to tag the post of this user',
+	`unkmail` boolean NOT NULL DEFAULT '0' COMMENT 'Permit unknown people to send private mails to this user',
+	`cntunkmail` int unsigned NOT NULL DEFAULT 10 COMMENT '',
+	`notify-flags` smallint unsigned NOT NULL DEFAULT 65535 COMMENT 'email notification options',
+	`page-flags` tinyint unsigned NOT NULL DEFAULT 0 COMMENT 'page/profile type',
+	`account-type` tinyint unsigned NOT NULL DEFAULT 0 COMMENT '',
+	`prvnets` boolean NOT NULL DEFAULT '0' COMMENT '',
+	`pwdreset` varchar(255) COMMENT 'Password reset request token',
+	`pwdreset_time` datetime COMMENT 'Timestamp of the last password reset request',
+	`maxreq` int unsigned NOT NULL DEFAULT 10 COMMENT '',
+	`expire` int unsigned NOT NULL DEFAULT 0 COMMENT '',
+	`account_removed` boolean NOT NULL DEFAULT '0' COMMENT 'if 1 the account is removed',
+	`account_expired` boolean NOT NULL DEFAULT '0' COMMENT '',
+	`account_expires_on` datetime NOT NULL DEFAULT '0001-01-01 00:00:00' COMMENT 'timestamp when account expires and will be deleted',
+	`expire_notification_sent` datetime NOT NULL DEFAULT '0001-01-01 00:00:00' COMMENT 'timestamp of last warning of account expiration',
+	`def_gid` int unsigned NOT NULL DEFAULT 0 COMMENT '',
+	`allow_cid` mediumtext COMMENT 'default permission for this user',
+	`allow_gid` mediumtext COMMENT 'default permission for this user',
+	`deny_cid` mediumtext COMMENT 'default permission for this user',
+	`deny_gid` mediumtext COMMENT 'default permission for this user',
+	`openidserver` text COMMENT '',
+	 PRIMARY KEY(`uid`),
+	 INDEX `nickname` (`nickname`(32)),
+	 INDEX `parent-uid` (`parent-uid`),
+	FOREIGN KEY (`parent-uid`) REFERENCES `user` (`uid`) ON UPDATE RESTRICT ON DELETE CASCADE
+) DEFAULT COLLATE utf8mb4_general_ci COMMENT='The local users';
+
 --
 -- TABLE contact
 --
@@ -135,6 +190,7 @@ CREATE TABLE IF NOT EXISTS `contact` (
 	 INDEX `uid_network_self_lastupdate` (`uid`,`network`,`self`,`last-update`),
 	 INDEX `uid_lastitem` (`uid`,`last-item`),
 	 INDEX `gsid` (`gsid`),
+	FOREIGN KEY (`uid`) REFERENCES `user` (`uid`) ON UPDATE RESTRICT ON DELETE CASCADE,
 	FOREIGN KEY (`gsid`) REFERENCES `gserver` (`id`) ON UPDATE RESTRICT ON DELETE RESTRICT
 ) DEFAULT COLLATE utf8mb4_general_ci COMMENT='contact table';
 
@@ -162,59 +218,6 @@ CREATE TABLE IF NOT EXISTS `tag` (
 	 INDEX `url` (`url`)
 ) DEFAULT COLLATE utf8mb4_general_ci COMMENT='tags and mentions';
 
---
--- TABLE user
---
-CREATE TABLE IF NOT EXISTS `user` (
-	`uid` mediumint unsigned NOT NULL auto_increment COMMENT 'sequential ID',
-	`parent-uid` mediumint unsigned NOT NULL DEFAULT 0 COMMENT 'The parent user that has full control about this user',
-	`guid` varchar(64) NOT NULL DEFAULT '' COMMENT 'A unique identifier for this user',
-	`username` varchar(255) NOT NULL DEFAULT '' COMMENT 'Name that this user is known by',
-	`password` varchar(255) NOT NULL DEFAULT '' COMMENT 'encrypted password',
-	`legacy_password` boolean NOT NULL DEFAULT '0' COMMENT 'Is the password hash double-hashed?',
-	`nickname` varchar(255) NOT NULL DEFAULT '' COMMENT 'nick- and user name',
-	`email` varchar(255) NOT NULL DEFAULT '' COMMENT 'the users email address',
-	`openid` varchar(255) NOT NULL DEFAULT '' COMMENT '',
-	`timezone` varchar(128) NOT NULL DEFAULT '' COMMENT 'PHP-legal timezone',
-	`language` varchar(32) NOT NULL DEFAULT 'en' COMMENT 'default language',
-	`register_date` datetime NOT NULL DEFAULT '0001-01-01 00:00:00' COMMENT 'timestamp of registration',
-	`login_date` datetime NOT NULL DEFAULT '0001-01-01 00:00:00' COMMENT 'timestamp of last login',
-	`default-location` varchar(255) NOT NULL DEFAULT '' COMMENT 'Default for item.location',
-	`allow_location` boolean NOT NULL DEFAULT '0' COMMENT '1 allows to display the location',
-	`theme` varchar(255) NOT NULL DEFAULT '' COMMENT 'user theme preference',
-	`pubkey` text COMMENT 'RSA public key 4096 bit',
-	`prvkey` text COMMENT 'RSA private key 4096 bit',
-	`spubkey` text COMMENT '',
-	`sprvkey` text COMMENT '',
-	`verified` boolean NOT NULL DEFAULT '0' COMMENT 'user is verified through email',
-	`blocked` boolean NOT NULL DEFAULT '0' COMMENT '1 for user is blocked',
-	`blockwall` boolean NOT NULL DEFAULT '0' COMMENT 'Prohibit contacts to post to the profile page of the user',
-	`hidewall` boolean NOT NULL DEFAULT '0' COMMENT 'Hide profile details from unkown viewers',
-	`blocktags` boolean NOT NULL DEFAULT '0' COMMENT 'Prohibit contacts to tag the post of this user',
-	`unkmail` boolean NOT NULL DEFAULT '0' COMMENT 'Permit unknown people to send private mails to this user',
-	`cntunkmail` int unsigned NOT NULL DEFAULT 10 COMMENT '',
-	`notify-flags` smallint unsigned NOT NULL DEFAULT 65535 COMMENT 'email notification options',
-	`page-flags` tinyint unsigned NOT NULL DEFAULT 0 COMMENT 'page/profile type',
-	`account-type` tinyint unsigned NOT NULL DEFAULT 0 COMMENT '',
-	`prvnets` boolean NOT NULL DEFAULT '0' COMMENT '',
-	`pwdreset` varchar(255) COMMENT 'Password reset request token',
-	`pwdreset_time` datetime COMMENT 'Timestamp of the last password reset request',
-	`maxreq` int unsigned NOT NULL DEFAULT 10 COMMENT '',
-	`expire` int unsigned NOT NULL DEFAULT 0 COMMENT '',
-	`account_removed` boolean NOT NULL DEFAULT '0' COMMENT 'if 1 the account is removed',
-	`account_expired` boolean NOT NULL DEFAULT '0' COMMENT '',
-	`account_expires_on` datetime NOT NULL DEFAULT '0001-01-01 00:00:00' COMMENT 'timestamp when account expires and will be deleted',
-	`expire_notification_sent` datetime NOT NULL DEFAULT '0001-01-01 00:00:00' COMMENT 'timestamp of last warning of account expiration',
-	`def_gid` int unsigned NOT NULL DEFAULT 0 COMMENT '',
-	`allow_cid` mediumtext COMMENT 'default permission for this user',
-	`allow_gid` mediumtext COMMENT 'default permission for this user',
-	`deny_cid` mediumtext COMMENT 'default permission for this user',
-	`deny_gid` mediumtext COMMENT 'default permission for this user',
-	`openidserver` text COMMENT '',
-	 PRIMARY KEY(`uid`),
-	 INDEX `nickname` (`nickname`(32))
-) DEFAULT COLLATE utf8mb4_general_ci COMMENT='The local users';
-
 --
 -- TABLE clients
 --
@@ -241,7 +244,8 @@ CREATE TABLE IF NOT EXISTS `permissionset` (
 	`deny_cid` mediumtext COMMENT 'Access Control - list of denied contact.id',
 	`deny_gid` mediumtext COMMENT 'Access Control - list of denied groups',
 	 PRIMARY KEY(`id`),
-	 INDEX `uid_allow_cid_allow_gid_deny_cid_deny_gid` (`allow_cid`(50),`allow_gid`(30),`deny_cid`(50),`deny_gid`(30))
+	 INDEX `uid_allow_cid_allow_gid_deny_cid_deny_gid` (`uid`,`allow_cid`(50),`allow_gid`(30),`deny_cid`(50),`deny_gid`(30)),
+	FOREIGN KEY (`uid`) REFERENCES `user` (`uid`) ON UPDATE RESTRICT ON DELETE CASCADE
 ) DEFAULT COLLATE utf8mb4_general_ci COMMENT='';
 
 --
@@ -484,6 +488,7 @@ CREATE TABLE IF NOT EXISTS `event` (
 	 PRIMARY KEY(`id`),
 	 INDEX `uid_start` (`uid`,`start`),
 	 INDEX `cid` (`cid`),
+	FOREIGN KEY (`uid`) REFERENCES `user` (`uid`) ON UPDATE RESTRICT ON DELETE CASCADE,
 	FOREIGN KEY (`cid`) REFERENCES `contact` (`id`) ON UPDATE RESTRICT ON DELETE CASCADE
 ) DEFAULT COLLATE utf8mb4_general_ci COMMENT='Events';
 
@@ -745,6 +750,7 @@ CREATE TABLE IF NOT EXISTS `item` (
 	FOREIGN KEY (`parent-uri-id`) REFERENCES `item-uri` (`id`) ON UPDATE RESTRICT ON DELETE CASCADE,
 	FOREIGN KEY (`thr-parent-id`) REFERENCES `item-uri` (`id`) ON UPDATE RESTRICT ON DELETE CASCADE,
 	FOREIGN KEY (`causer-id`) REFERENCES `contact` (`id`) ON UPDATE RESTRICT ON DELETE RESTRICT,
+	FOREIGN KEY (`uid`) REFERENCES `user` (`uid`) ON UPDATE RESTRICT ON DELETE CASCADE,
 	FOREIGN KEY (`psid`) REFERENCES `permissionset` (`id`) ON UPDATE RESTRICT ON DELETE RESTRICT
 ) DEFAULT COLLATE utf8mb4_general_ci COMMENT='Structure for all posts';
 
@@ -946,7 +952,8 @@ CREATE TABLE IF NOT EXISTS `openwebauth-token` (
 	`meta` varchar(255) NOT NULL DEFAULT '' COMMENT '',
 	`created` datetime NOT NULL DEFAULT '0001-01-01 00:00:00' COMMENT 'datetime of creation',
 	 PRIMARY KEY(`id`),
-	 INDEX `uid` (`uid`)
+	 INDEX `uid` (`uid`),
+	FOREIGN KEY (`uid`) REFERENCES `user` (`uid`) ON UPDATE RESTRICT ON DELETE CASCADE
 ) DEFAULT COLLATE utf8mb4_general_ci COMMENT='Store OpenWebAuth token to verify contacts';
 
 --
@@ -982,11 +989,11 @@ CREATE TABLE IF NOT EXISTS `participation` (
 -- TABLE pconfig
 --
 CREATE TABLE IF NOT EXISTS `pconfig` (
-	`id` int unsigned NOT NULL auto_increment COMMENT '',
+	`id` int unsigned NOT NULL auto_increment COMMENT 'Primary key',
 	`uid` mediumint unsigned NOT NULL DEFAULT 0 COMMENT 'User id',
-	`cat` varbinary(50) NOT NULL DEFAULT '' COMMENT '',
-	`k` varbinary(100) NOT NULL DEFAULT '' COMMENT '',
-	`v` mediumtext COMMENT '',
+	`cat` varchar(50) NOT NULL DEFAULT '' COMMENT 'Category',
+	`k` varchar(100) NOT NULL DEFAULT '' COMMENT 'Key',
+	`v` mediumtext COMMENT 'Value',
 	 PRIMARY KEY(`id`),
 	 UNIQUE INDEX `uid_cat_k` (`uid`,`cat`,`k`),
 	FOREIGN KEY (`uid`) REFERENCES `user` (`uid`) ON UPDATE RESTRICT ON DELETE CASCADE
@@ -1029,6 +1036,7 @@ CREATE TABLE IF NOT EXISTS `photo` (
 	 INDEX `uid_album_scale_created` (`uid`,`album`(32),`scale`,`created`),
 	 INDEX `uid_album_resource-id_created` (`uid`,`album`(32),`resource-id`,`created`),
 	 INDEX `resource-id` (`resource-id`),
+	FOREIGN KEY (`uid`) REFERENCES `user` (`uid`) ON UPDATE RESTRICT ON DELETE CASCADE,
 	FOREIGN KEY (`contact-id`) REFERENCES `contact` (`id`) ON UPDATE RESTRICT ON DELETE RESTRICT
 ) DEFAULT COLLATE utf8mb4_general_ci COMMENT='photo storage';
 
@@ -1042,7 +1050,9 @@ CREATE TABLE IF NOT EXISTS `post-category` (
 	`tid` int unsigned NOT NULL DEFAULT 0 COMMENT '',
 	 PRIMARY KEY(`uri-id`,`uid`,`type`,`tid`),
 	 INDEX `uri-id` (`tid`),
+	 INDEX `uid` (`uid`),
 	FOREIGN KEY (`uri-id`) REFERENCES `item-uri` (`id`) ON UPDATE RESTRICT ON DELETE CASCADE,
+	FOREIGN KEY (`uid`) REFERENCES `user` (`uid`) ON UPDATE RESTRICT ON DELETE CASCADE,
 	FOREIGN KEY (`tid`) REFERENCES `tag` (`id`) ON UPDATE RESTRICT ON DELETE RESTRICT
 ) DEFAULT COLLATE utf8mb4_general_ci COMMENT='post relation to categories';
 
@@ -1102,6 +1112,28 @@ CREATE TABLE IF NOT EXISTS `post-tag` (
 	FOREIGN KEY (`cid`) REFERENCES `contact` (`id`) ON UPDATE RESTRICT ON DELETE RESTRICT
 ) DEFAULT COLLATE utf8mb4_general_ci COMMENT='post relation to tags';
 
+--
+-- TABLE post-user
+--
+CREATE TABLE IF NOT EXISTS `post-user` (
+	`uri-id` int unsigned NOT NULL COMMENT 'Id of the item-uri table entry that contains the item uri',
+	`uid` mediumint unsigned NOT NULL COMMENT 'Owner id which owns this copy of the item',
+	`contact-id` int unsigned NOT NULL DEFAULT 0 COMMENT 'contact.id',
+	`unseen` boolean NOT NULL DEFAULT '1' COMMENT 'post has not been seen',
+	`hidden` boolean NOT NULL DEFAULT '0' COMMENT 'Marker to hide the post from the user',
+	`notification-type` tinyint unsigned NOT NULL DEFAULT 0 COMMENT '',
+	`origin` boolean NOT NULL DEFAULT '0' COMMENT 'item originated at this site',
+	`psid` int unsigned COMMENT 'ID of the permission set of this post',
+	 PRIMARY KEY(`uid`,`uri-id`),
+	 INDEX `uri-id` (`uri-id`),
+	 INDEX `contact-id` (`contact-id`),
+	 INDEX `psid` (`psid`),
+	FOREIGN KEY (`uri-id`) REFERENCES `item-uri` (`id`) ON UPDATE RESTRICT ON DELETE CASCADE,
+	FOREIGN KEY (`uid`) REFERENCES `user` (`uid`) ON UPDATE RESTRICT ON DELETE CASCADE,
+	FOREIGN KEY (`contact-id`) REFERENCES `contact` (`id`) ON UPDATE RESTRICT ON DELETE CASCADE,
+	FOREIGN KEY (`psid`) REFERENCES `permissionset` (`id`) ON UPDATE RESTRICT ON DELETE RESTRICT
+) DEFAULT COLLATE utf8mb4_general_ci COMMENT='User specific post data';
+
 --
 -- TABLE process
 --
@@ -1316,7 +1348,8 @@ CREATE TABLE IF NOT EXISTS `thread` (
 	 INDEX `private_wall_origin_commented` (`private`,`wall`,`origin`,`commented`),
 	 INDEX `uri-id` (`uri-id`),
 	FOREIGN KEY (`iid`) REFERENCES `item` (`id`) ON UPDATE RESTRICT ON DELETE CASCADE,
-	FOREIGN KEY (`uri-id`) REFERENCES `item-uri` (`id`) ON UPDATE RESTRICT ON DELETE CASCADE
+	FOREIGN KEY (`uri-id`) REFERENCES `item-uri` (`id`) ON UPDATE RESTRICT ON DELETE CASCADE,
+	FOREIGN KEY (`uid`) REFERENCES `user` (`uid`) ON UPDATE RESTRICT ON DELETE CASCADE
 ) DEFAULT COLLATE utf8mb4_general_ci COMMENT='Thread related data';
 
 --
diff --git a/src/Database/DBStructure.php b/src/Database/DBStructure.php
index bdd8cc208..6f3fe5dba 100644
--- a/src/Database/DBStructure.php
+++ b/src/Database/DBStructure.php
@@ -170,6 +170,34 @@ class DBStructure
 		return $definition;
 	}
 
+	/**
+	 * Get field data for the given table
+	 *
+	 * @param string $table
+	 * @param array $data data fields
+	 * @return array fields for the given
+	 */
+	public static function getFieldsForTable(string $table, array $data = [])
+	{
+		$definition = DBStructure::definition('', false);
+		if (empty($definition[$table])) {
+			return [];
+		}
+
+		$fieldnames = array_keys($definition[$table]['fields']);
+
+		$fields = [];
+
+		// Assign all field that are present in the table
+		foreach ($fieldnames as $field) {
+			if (isset($data[$field])) {
+				$fields[$field] = $data[$field];
+			}
+		}
+
+		return $fields;
+	}
+
 	private static function createTable($name, $structure, $verbose, $action)
 	{
 		$r = true;
@@ -322,7 +350,7 @@ class DBStructure
 
 		$errors = '';
 
-		Logger::log('updating structure', Logger::DEBUG);
+		Logger::info('updating structure');
 
 		// Get the current structure
 		$database = [];
@@ -335,7 +363,7 @@ class DBStructure
 			foreach ($tables AS $table) {
 				$table = current($table);
 
-				Logger::log(sprintf('updating structure for table %s ...', $table), Logger::DEBUG);
+				Logger::info('updating structure', ['table' => $table]);
 				$database[$table] = self::tableStructure($table);
 			}
 		}
@@ -1026,6 +1054,19 @@ class DBStructure
 			}
 		}
 
+		if (self::existsTable('user') && !DBA::exists('user', ['uid' => 0])) {
+			$user = [
+				"verified" => true,
+				"page-flags" => User::PAGE_FLAGS_SOAPBOX,
+				"account-type" => User::ACCOUNT_TYPE_RELAY,
+			];
+			DBA::insert('user', $user);
+			$lastid = DBA::lastInsertId();
+			if ($lastid != 0) {
+				DBA::update('user', ['uid' => 0], ['uid' => $lastid]);
+			}
+		}
+
 		if (self::existsTable('contact') && !DBA::exists('contact', ['id' => 0])) {
 			DBA::insert('contact', ['nurl' => '']);
 			$lastid = DBA::lastInsertId();
diff --git a/src/Model/Item.php b/src/Model/Item.php
index 9890c8a99..4e0cc5cd0 100644
--- a/src/Model/Item.php
+++ b/src/Model/Item.php
@@ -34,7 +34,7 @@ use Friendica\Core\Worker;
 use Friendica\Database\DBA;
 use Friendica\Database\DBStructure;
 use Friendica\DI;
-use Friendica\Model\Post\Category;
+use Friendica\Model\Post;
 use Friendica\Protocol\Activity;
 use Friendica\Protocol\ActivityPub;
 use Friendica\Protocol\Diaspora;
@@ -71,8 +71,6 @@ class Item
 	const PT_FETCHED = 75;
 	const PT_PERSONAL_NOTE = 128;
 
-	const LOCK_INSERT = 'item-insert';
-
 	// Field list that is used to display the items
 	const DISPLAY_FIELDLIST = [
 		'uid', 'id', 'parent', 'uri-id', 'uri', 'thr-parent', 'parent-uri', 'guid', 'network', 'gravity',
@@ -310,7 +308,7 @@ class Item
 		if (!array_key_exists('verb', $row) || in_array($row['verb'], ['', Activity::POST, Activity::SHARE])) {
 			// Build the file string out of the term entries
 			if (array_key_exists('file', $row) && empty($row['file'])) {
-				$row['file'] = Category::getTextByURIId($row['internal-uri-id'], $row['internal-uid']);
+				$row['file'] = Post\Category::getTextByURIId($row['internal-uri-id'], $row['internal-uid']);
 			}
 		}
 
@@ -911,6 +909,8 @@ class Item
 			return false;
 		}
 
+		$data_fields = $fields;
+
 		// To ensure the data integrity we do it in an transaction
 		DBA::transaction();
 
@@ -967,6 +967,8 @@ class Item
 		$notify_items = [];
 
 		while ($item = DBA::fetch($items)) {
+			Post\User::update($item['uri-id'], $item['uid'], $data_fields);
+
 			if (empty($content_fields['verb']) || !in_array($content_fields['verb'], self::ACTIVITIES)) {
 				if (!empty($content_fields['body'])) {
 					$content_fields['raw-body'] = trim($content_fields['raw-body'] ?? $content_fields['body']);
@@ -996,7 +998,7 @@ class Item
 			}
 
 			if (!is_null($files)) {
-				Category::storeTextByURIId($item['uri-id'], $item['uid'], $files);
+				Post\Category::storeTextByURIId($item['uri-id'], $item['uid'], $files);
 				if (!empty($item['file'])) {
 					DBA::update('item', ['file' => ''], ['id' => $item['id']]);
 				}
@@ -1056,8 +1058,10 @@ class Item
 			return;
 		}
 
-		$items = self::select(['id', 'uid'], $condition);
+		$items = self::select(['id', 'uid', 'uri-id'], $condition);
 		while ($item = self::fetch($items)) {
+			Post\User::update($item['uri-id'], $item['uid'], ['hidden' => true]);
+
 			// "Deleting" global items just means hiding them
 			if ($item['uid'] == 0) {
 				DBA::update('user-item', ['hidden' => true], ['iid' => $item['id'], 'uid' => $uid], true);
@@ -1158,7 +1162,7 @@ class Item
 		$item_fields = ['deleted' => true, 'edited' => DateTimeFormat::utcNow(), 'changed' => DateTimeFormat::utcNow()];
 		DBA::update('item', $item_fields, ['id' => $item['id']]);
 
-		Category::storeTextByURIId($item['uri-id'], $item['uid'], '');
+		Post\Category::storeTextByURIId($item['uri-id'], $item['uid'], '');
 		self::deleteThread($item['id'], $item['parent-uri']);
 
 		if (!self::exists(["`uri` = ? AND `uid` != 0 AND NOT `deleted`", $item['uri']])) {
@@ -1191,6 +1195,7 @@ class Item
 			// send the notification upstream/downstream
 			Worker::add(['priority' => $priority, 'dont_fork' => true], "Notifier", Delivery::DELETION, intval($item['id']));
 		} elseif ($item['uid'] != 0) {
+			Post\User::update($item['uri-id'], $item['uid'], ['hidden' => true]);
 
 			// When we delete just our local user copy of an item, we have to set a marker to hide it
 			$global_item = self::selectFirst(['id'], ['uri' => $item['uri'], 'uid' => 0, 'deleted' => false]);
@@ -1862,7 +1867,7 @@ class Item
 
 		// Attached file links
 		if (!empty($item['file'])) {
-			Category::storeTextByURIId($item['uri-id'], $item['uid'], $item['file']);
+			Post\Category::storeTextByURIId($item['uri-id'], $item['uid'], $item['file']);
 		}
 
 		unset($item['file']);
@@ -1888,16 +1893,9 @@ class Item
 			}
 		}
 
-		$locked = DI::lock()->acquire(self::LOCK_INSERT, 0);
-
-		if ($locked || DBA::lock('item')) {
+		if (Post\User::insert($item['uri-id'], $item['uid'], $item)) {
 			$condition = ['uri-id' => $item['uri-id'], 'uid' => $item['uid'], 'network' => $item['network']];
 			if (DBA::exists('item', $condition)) {
-				if ($locked) {
-					DI::lock()->release(self::LOCK_INSERT);
-				} else {
-					DBA::unlock();
-				}
 				Logger::notice('Item is already inserted - aborting', $condition);
 				return 0;
 			}
@@ -1906,15 +1904,9 @@ class Item
 
 			// When the item was successfully stored we fetch the ID of the item.
 			$current_post = DBA::lastInsertId();
-			if ($locked) {
-				DI::lock()->release(self::LOCK_INSERT);
-			} else {
-				DBA::unlock();
-			}
 		} else {
-			Logger::warning('Item lock had not been acquired');
-			$result = false;
-			$current_post = 0;
+			Logger::notice('Post-User is already inserted - aborting', ['uid' => $item['uid'], 'uri-id' => $item['uri-id']]);
+			return 0;
 		}
 
 		if (empty($current_post) || !DBA::isResult($result)) {
diff --git a/src/Model/Post/User.php b/src/Model/Post/User.php
new file mode 100644
index 000000000..840d020d6
--- /dev/null
+++ b/src/Model/Post/User.php
@@ -0,0 +1,91 @@
+<?php
+/**
+ * @copyright Copyright (C) 2020, Friendica
+ *
+ * @license GNU AGPL version 3 or any later version
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as
+ * published by the Free Software Foundation, either version 3 of the
+ * License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ *
+ */
+
+namespace Friendica\Model\Post;
+
+use Friendica\Database\DBA;
+use \BadMethodCallException;
+use Friendica\Core\Logger;
+use Friendica\Database\DBStructure;
+
+class User
+{
+	/**
+	 * Insert a new URI user entry
+	 *
+	 * @param integer $uri_id
+	 * @param integer $uid
+	 * @param array   $fields
+	 * @return bool
+	 * @throws \Exception
+	 */
+	public static function insert(int $uri_id, int $uid, array $data = [])
+	{
+		if (empty($uri_id)) {
+			throw new BadMethodCallException('Empty URI_id');
+		}
+
+		if (DBA::exists('post-user', ['uri-id' => $uri_id, 'uid' => $uid])) {
+			return false;
+		}
+
+		$fields = DBStructure::getFieldsForTable('post-user', $data);
+
+		// Additionally assign the key fields
+		$fields['uri-id'] = $uri_id;
+		$fields['uid'] = $uid;
+
+		// Public posts are always seen
+		if ($uid == 0) {
+			$fields['unseen'] = false;
+		}
+
+		return DBA::insert('post-user', $fields);
+	}
+
+	/**
+	 * Update a URI user entry
+	 *
+	 * @param integer $uri_id
+	 * @param integer $uid
+	 * @param array   $fields
+	 * @return bool
+	 * @throws \Exception
+	 */
+	public static function update(int $uri_id, int $uid, array $data = [])
+	{
+		if (empty($uri_id)) {
+			throw new BadMethodCallException('Empty URI_id');
+		}
+
+		$fields = DBStructure::getFieldsForTable('post-user', $data);
+
+		// Remove the key fields
+		unset($fields['uri-id']);
+		unset($fields['uid']);
+
+		if (empty($fields)) {
+			return true;
+		}
+
+		return DBA::update('post-user', $fields, ['uri-id' => $uri_id, 'uid' => $uid], true);
+	}
+}
diff --git a/src/Model/User.php b/src/Model/User.php
index 39f9dc2a1..2b7018950 100644
--- a/src/Model/User.php
+++ b/src/Model/User.php
@@ -144,6 +144,26 @@ class User
 		$system['sprvkey'] = $system['uprvkey'] = $system['prvkey'];
 		$system['spubkey'] = $system['upubkey'] = $system['pubkey'];
 		$system['nickname'] = $system['nick'];
+
+		// Ensure that the user contains data
+		$user = DBA::selectFirst('user', ['prvkey'], ['uid' => 0]);
+		if (empty($user['prvkey'])) {
+			$fields = [
+				'username' => $system['name'],
+				'nickname' => $system['nick'],
+				'register_date' => $system['created'],
+				'pubkey' => $system['pubkey'],
+				'prvkey' => $system['prvkey'],
+				'spubkey' => $system['spubkey'],
+				'sprvkey' => $system['sprvkey'],
+				'verified' => true,
+				'page-flags' => User::PAGE_FLAGS_SOAPBOX,
+				'account-type' => User::ACCOUNT_TYPE_RELAY,
+			];
+
+			DBA::update('user', $fields, ['uid' => 0]);
+		}
+
 		return $system;
 	}
 
@@ -215,7 +235,7 @@ class User
 		// List of possible actor names
 		$possible_accounts = ['friendica', 'actor', 'system', 'internal'];
 		foreach ($possible_accounts as $name) {
-			if (!DBA::exists('user', ['nickname' => $name, 'account_removed' => false, 'expire']) &&
+			if (!DBA::exists('user', ['nickname' => $name, 'account_removed' => false, 'expire' => false]) &&
 				!DBA::exists('userd', ['username' => $name])) {
 				DI::config()->set('system', 'actor_name', $name);
 				return $name;
diff --git a/src/Model/UserItem.php b/src/Model/UserItem.php
index b7dfec4b1..38e9adc6e 100644
--- a/src/Model/UserItem.php
+++ b/src/Model/UserItem.php
@@ -156,7 +156,9 @@ class UserItem
 
 		Logger::info('Set notification', ['iid' => $item['id'], 'uid' => $uid, 'notification-type' => $notification_type]);
 
-		DBA::update('user-item', ['notification-type' => $notification_type], ['iid' => $item['id'], 'uid' => $uid], true);
+		$fields = ['notification-type' => $notification_type];
+		Post\User::update($item['uri-id'], $uid, $fields);
+		DBA::update('user-item', $fields, ['iid' => $item['id'], 'uid' => $uid], true);
 	}
 
 	/**
diff --git a/src/Worker/ExpireAndRemoveUsers.php b/src/Worker/ExpireAndRemoveUsers.php
index c8344b6fd..f28f410b9 100644
--- a/src/Worker/ExpireAndRemoveUsers.php
+++ b/src/Worker/ExpireAndRemoveUsers.php
@@ -33,9 +33,14 @@ class ExpireAndRemoveUsers
 	public static function execute()
 	{
 		// expire any expired regular accounts. Don't expire forums.
-		$condition = ["NOT `account_expired` AND `account_expires_on` > ? AND `account_expires_on` < UTC_TIMESTAMP() AND `page-flags` = 0", DBA::NULL_DATETIME];
+		$condition = ["NOT `account_expired` AND `account_expires_on` > ? AND `account_expires_on` < UTC_TIMESTAMP() AND `page-flags` = ? AND `uid` != ?",
+			DBA::NULL_DATETIME, User::PAGE_FLAGS_NORMAL, 0];
 		DBA::update('user', ['account_expired' => true], $condition);
 
+		// Ensure to never remove the user with uid=0
+		DBA::update('user', ['account_expired' => false, 'account_removed' => false,
+			'account_expires_on' => DBA::NULL_DATETIME], ['uid' => 0]);
+
 		// Remove any freshly expired account
 		$users = DBA::select('user', ['uid'], ['account_expired' => true, 'account_removed' => false]);
 		while ($user = DBA::fetch($users)) {
diff --git a/static/dbstructure.config.php b/static/dbstructure.config.php
index 290550174..e952675fe 100644
--- a/static/dbstructure.config.php
+++ b/static/dbstructure.config.php
@@ -20,6 +20,7 @@
  * Main database structure configuration file.
  *
  * Here are described all the tables, fields and indexes Friendica needs to work.
+ * The entry order is mostly alphabetic - with the exception of tables that are used in foreign keys.
  *
  * Syntax (braces indicate optionale values):
  * "<table name>" => [
@@ -54,7 +55,7 @@
 use Friendica\Database\DBA;
 
 if (!defined('DB_UPDATE_VERSION')) {
-	define('DB_UPDATE_VERSION', 1375);
+	define('DB_UPDATE_VERSION', 1376);
 }
 
 return [
@@ -89,11 +90,67 @@ return [
 			"nurl" => ["UNIQUE", "nurl(190)"],
 		]
 	],
+	"user" => [
+		"comment" => "The local users",
+		"fields" => [
+			"uid" => ["type" => "mediumint unsigned", "not null" => "1", "extra" => "auto_increment", "primary" => "1", "comment" => "sequential ID"],
+			"parent-uid" => ["type" => "mediumint unsigned", "foreign" => ["user" => "uid"],
+				"comment" => "The parent user that has full control about this user"],
+			"guid" => ["type" => "varchar(64)", "not null" => "1", "default" => "", "comment" => "A unique identifier for this user"],
+			"username" => ["type" => "varchar(255)", "not null" => "1", "default" => "", "comment" => "Name that this user is known by"],
+			"password" => ["type" => "varchar(255)", "not null" => "1", "default" => "", "comment" => "encrypted password"],
+			"legacy_password" => ["type" => "boolean", "not null" => "1", "default" => "0", "comment" => "Is the password hash double-hashed?"],
+			"nickname" => ["type" => "varchar(255)", "not null" => "1", "default" => "", "comment" => "nick- and user name"],
+			"email" => ["type" => "varchar(255)", "not null" => "1", "default" => "", "comment" => "the users email address"],
+			"openid" => ["type" => "varchar(255)", "not null" => "1", "default" => "", "comment" => ""],
+			"timezone" => ["type" => "varchar(128)", "not null" => "1", "default" => "", "comment" => "PHP-legal timezone"],
+			"language" => ["type" => "varchar(32)", "not null" => "1", "default" => "en", "comment" => "default language"],
+			"register_date" => ["type" => "datetime", "not null" => "1", "default" => DBA::NULL_DATETIME, "comment" => "timestamp of registration"],
+			"login_date" => ["type" => "datetime", "not null" => "1", "default" => DBA::NULL_DATETIME, "comment" => "timestamp of last login"],
+			"default-location" => ["type" => "varchar(255)", "not null" => "1", "default" => "", "comment" => "Default for item.location"],
+			"allow_location" => ["type" => "boolean", "not null" => "1", "default" => "0", "comment" => "1 allows to display the location"],
+			"theme" => ["type" => "varchar(255)", "not null" => "1", "default" => "", "comment" => "user theme preference"],
+			"pubkey" => ["type" => "text", "comment" => "RSA public key 4096 bit"],
+			"prvkey" => ["type" => "text", "comment" => "RSA private key 4096 bit"],
+			"spubkey" => ["type" => "text", "comment" => ""],
+			"sprvkey" => ["type" => "text", "comment" => ""],
+			"verified" => ["type" => "boolean", "not null" => "1", "default" => "0", "comment" => "user is verified through email"],
+			"blocked" => ["type" => "boolean", "not null" => "1", "default" => "0", "comment" => "1 for user is blocked"],
+			"blockwall" => ["type" => "boolean", "not null" => "1", "default" => "0", "comment" => "Prohibit contacts to post to the profile page of the user"],
+			"hidewall" => ["type" => "boolean", "not null" => "1", "default" => "0", "comment" => "Hide profile details from unkown viewers"],
+			"blocktags" => ["type" => "boolean", "not null" => "1", "default" => "0", "comment" => "Prohibit contacts to tag the post of this user"],
+			"unkmail" => ["type" => "boolean", "not null" => "1", "default" => "0", "comment" => "Permit unknown people to send private mails to this user"],
+			"cntunkmail" => ["type" => "int unsigned", "not null" => "1", "default" => "10", "comment" => ""],
+			"notify-flags" => ["type" => "smallint unsigned", "not null" => "1", "default" => "65535", "comment" => "email notification options"],
+			"page-flags" => ["type" => "tinyint unsigned", "not null" => "1", "default" => "0", "comment" => "page/profile type"],
+			"account-type" => ["type" => "tinyint unsigned", "not null" => "1", "default" => "0", "comment" => ""],
+			"prvnets" => ["type" => "boolean", "not null" => "1", "default" => "0", "comment" => ""],
+			"pwdreset" => ["type" => "varchar(255)", "comment" => "Password reset request token"],
+			"pwdreset_time" => ["type" => "datetime", "comment" => "Timestamp of the last password reset request"],
+			"maxreq" => ["type" => "int unsigned", "not null" => "1", "default" => "10", "comment" => ""],
+			"expire" => ["type" => "int unsigned", "not null" => "1", "default" => "0", "comment" => ""],
+			"account_removed" => ["type" => "boolean", "not null" => "1", "default" => "0", "comment" => "if 1 the account is removed"],
+			"account_expired" => ["type" => "boolean", "not null" => "1", "default" => "0", "comment" => ""],
+			"account_expires_on" => ["type" => "datetime", "not null" => "1", "default" => DBA::NULL_DATETIME, "comment" => "timestamp when account expires and will be deleted"],
+			"expire_notification_sent" => ["type" => "datetime", "not null" => "1", "default" => DBA::NULL_DATETIME, "comment" => "timestamp of last warning of account expiration"],
+			"def_gid" => ["type" => "int unsigned", "not null" => "1", "default" => "0", "comment" => ""],
+			"allow_cid" => ["type" => "mediumtext", "comment" => "default permission for this user"],
+			"allow_gid" => ["type" => "mediumtext", "comment" => "default permission for this user"],
+			"deny_cid" => ["type" => "mediumtext", "comment" => "default permission for this user"],
+			"deny_gid" => ["type" => "mediumtext", "comment" => "default permission for this user"],
+			"openidserver" => ["type" => "text", "comment" => ""],
+		],
+		"indexes" => [
+			"PRIMARY" => ["uid"],
+			"nickname" => ["nickname(32)"],
+			"parent-uid" => ["parent-uid"],
+		]
+	],
 	"contact" => [
 		"comment" => "contact table",
 		"fields" => [
 			"id" => ["type" => "int unsigned", "not null" => "1", "extra" => "auto_increment", "primary" => "1", "comment" => "sequential ID"],
-			"uid" => ["type" => "mediumint unsigned", "not null" => "1", "default" => "0", "relation" => ["user" => "uid"], "comment" => "Owner User id"],
+			"uid" => ["type" => "mediumint unsigned", "not null" => "1", "default" => "0", "foreign" => ["user" => "uid"], "comment" => "Owner User id"],
 			"created" => ["type" => "datetime", "not null" => "1", "default" => DBA::NULL_DATETIME, "comment" => ""],
 			"updated" => ["type" => "datetime", "default" => DBA::NULL_DATETIME, "comment" => "Date of last contact update"],
 			"self" => ["type" => "boolean", "not null" => "1", "default" => "0", "comment" => "1 if the contact is the user him/her self"],
@@ -220,61 +277,6 @@ return [
 			"url" => ["url"]
 		]
 	],
-	"user" => [
-		"comment" => "The local users",
-		"fields" => [
-			"uid" => ["type" => "mediumint unsigned", "not null" => "1", "extra" => "auto_increment", "primary" => "1", "comment" => "sequential ID"],
-			"parent-uid" => ["type" => "mediumint unsigned", "not null" => "1", "default" => "0", "relation" => ["user" => "uid"],
-				"comment" => "The parent user that has full control about this user"],
-			"guid" => ["type" => "varchar(64)", "not null" => "1", "default" => "", "comment" => "A unique identifier for this user"],
-			"username" => ["type" => "varchar(255)", "not null" => "1", "default" => "", "comment" => "Name that this user is known by"],
-			"password" => ["type" => "varchar(255)", "not null" => "1", "default" => "", "comment" => "encrypted password"],
-			"legacy_password" => ["type" => "boolean", "not null" => "1", "default" => "0", "comment" => "Is the password hash double-hashed?"],
-			"nickname" => ["type" => "varchar(255)", "not null" => "1", "default" => "", "comment" => "nick- and user name"],
-			"email" => ["type" => "varchar(255)", "not null" => "1", "default" => "", "comment" => "the users email address"],
-			"openid" => ["type" => "varchar(255)", "not null" => "1", "default" => "", "comment" => ""],
-			"timezone" => ["type" => "varchar(128)", "not null" => "1", "default" => "", "comment" => "PHP-legal timezone"],
-			"language" => ["type" => "varchar(32)", "not null" => "1", "default" => "en", "comment" => "default language"],
-			"register_date" => ["type" => "datetime", "not null" => "1", "default" => DBA::NULL_DATETIME, "comment" => "timestamp of registration"],
-			"login_date" => ["type" => "datetime", "not null" => "1", "default" => DBA::NULL_DATETIME, "comment" => "timestamp of last login"],
-			"default-location" => ["type" => "varchar(255)", "not null" => "1", "default" => "", "comment" => "Default for item.location"],
-			"allow_location" => ["type" => "boolean", "not null" => "1", "default" => "0", "comment" => "1 allows to display the location"],
-			"theme" => ["type" => "varchar(255)", "not null" => "1", "default" => "", "comment" => "user theme preference"],
-			"pubkey" => ["type" => "text", "comment" => "RSA public key 4096 bit"],
-			"prvkey" => ["type" => "text", "comment" => "RSA private key 4096 bit"],
-			"spubkey" => ["type" => "text", "comment" => ""],
-			"sprvkey" => ["type" => "text", "comment" => ""],
-			"verified" => ["type" => "boolean", "not null" => "1", "default" => "0", "comment" => "user is verified through email"],
-			"blocked" => ["type" => "boolean", "not null" => "1", "default" => "0", "comment" => "1 for user is blocked"],
-			"blockwall" => ["type" => "boolean", "not null" => "1", "default" => "0", "comment" => "Prohibit contacts to post to the profile page of the user"],
-			"hidewall" => ["type" => "boolean", "not null" => "1", "default" => "0", "comment" => "Hide profile details from unkown viewers"],
-			"blocktags" => ["type" => "boolean", "not null" => "1", "default" => "0", "comment" => "Prohibit contacts to tag the post of this user"],
-			"unkmail" => ["type" => "boolean", "not null" => "1", "default" => "0", "comment" => "Permit unknown people to send private mails to this user"],
-			"cntunkmail" => ["type" => "int unsigned", "not null" => "1", "default" => "10", "comment" => ""],
-			"notify-flags" => ["type" => "smallint unsigned", "not null" => "1", "default" => "65535", "comment" => "email notification options"],
-			"page-flags" => ["type" => "tinyint unsigned", "not null" => "1", "default" => "0", "comment" => "page/profile type"],
-			"account-type" => ["type" => "tinyint unsigned", "not null" => "1", "default" => "0", "comment" => ""],
-			"prvnets" => ["type" => "boolean", "not null" => "1", "default" => "0", "comment" => ""],
-			"pwdreset" => ["type" => "varchar(255)", "comment" => "Password reset request token"],
-			"pwdreset_time" => ["type" => "datetime", "comment" => "Timestamp of the last password reset request"],
-			"maxreq" => ["type" => "int unsigned", "not null" => "1", "default" => "10", "comment" => ""],
-			"expire" => ["type" => "int unsigned", "not null" => "1", "default" => "0", "comment" => ""],
-			"account_removed" => ["type" => "boolean", "not null" => "1", "default" => "0", "comment" => "if 1 the account is removed"],
-			"account_expired" => ["type" => "boolean", "not null" => "1", "default" => "0", "comment" => ""],
-			"account_expires_on" => ["type" => "datetime", "not null" => "1", "default" => DBA::NULL_DATETIME, "comment" => "timestamp when account expires and will be deleted"],
-			"expire_notification_sent" => ["type" => "datetime", "not null" => "1", "default" => DBA::NULL_DATETIME, "comment" => "timestamp of last warning of account expiration"],
-			"def_gid" => ["type" => "int unsigned", "not null" => "1", "default" => "0", "comment" => ""],
-			"allow_cid" => ["type" => "mediumtext", "comment" => "default permission for this user"],
-			"allow_gid" => ["type" => "mediumtext", "comment" => "default permission for this user"],
-			"deny_cid" => ["type" => "mediumtext", "comment" => "default permission for this user"],
-			"deny_gid" => ["type" => "mediumtext", "comment" => "default permission for this user"],
-			"openidserver" => ["type" => "text", "comment" => ""],
-		],
-		"indexes" => [
-			"PRIMARY" => ["uid"],
-			"nickname" => ["nickname(32)"],
-		]
-	],
 	"clients" => [
 		"comment" => "OAuth usage",
 		"fields" => [
@@ -294,7 +296,7 @@ return [
 		"comment" => "",
 		"fields" => [
 			"id" => ["type" => "int unsigned", "not null" => "1", "extra" => "auto_increment", "primary" => "1", "comment" => "sequential ID"],
-			"uid" => ["type" => "mediumint unsigned", "not null" => "1", "default" => "0", "relation" => ["user" => "uid"], "comment" => "Owner id of this permission set"],
+			"uid" => ["type" => "mediumint unsigned", "not null" => "1", "default" => "0", "foreign" => ["user" => "uid"], "comment" => "Owner id of this permission set"],
 			"allow_cid" => ["type" => "mediumtext", "comment" => "Access Control - list of allowed contact.id '<19><78>'"],
 			"allow_gid" => ["type" => "mediumtext", "comment" => "Access Control - list of allowed groups"],
 			"deny_cid" => ["type" => "mediumtext", "comment" => "Access Control - list of denied contact.id"],
@@ -302,7 +304,7 @@ return [
 		],
 		"indexes" => [
 			"PRIMARY" => ["id"],
-			"uid_allow_cid_allow_gid_deny_cid_deny_gid" => ["allow_cid(50)", "allow_gid(30)", "deny_cid(50)", "deny_gid(30)"],
+			"uid_allow_cid_allow_gid_deny_cid_deny_gid" => ["uid", "allow_cid(50)", "allow_gid(30)", "deny_cid(50)", "deny_gid(30)"],
 		]
 	],
 	// Main tables
@@ -529,7 +531,7 @@ return [
 		"fields" => [
 			"id" => ["type" => "int unsigned", "not null" => "1", "extra" => "auto_increment", "primary" => "1", "comment" => "sequential ID"],
 			"guid" => ["type" => "varchar(255)", "not null" => "1", "default" => "", "comment" => ""],
-			"uid" => ["type" => "mediumint unsigned", "not null" => "1", "default" => "0", "relation" => ["user" => "uid"], "comment" => "Owner User id"],
+			"uid" => ["type" => "mediumint unsigned", "not null" => "1", "default" => "0", "foreign" => ["user" => "uid"], "comment" => "Owner User id"],
 			"cid" => ["type" => "int unsigned", "not null" => "1", "default" => "0", "foreign" => ["contact" => "id"], "comment" => "contact_id (ID of the contact in contact table)"],
 			"uri" => ["type" => "varchar(255)", "not null" => "1", "default" => "", "comment" => ""],
 			"created" => ["type" => "datetime", "not null" => "1", "default" => DBA::NULL_DATETIME, "comment" => "creation time"],
@@ -734,7 +736,7 @@ return [
 			"moderated" => ["type" => "boolean", "not null" => "1", "default" => "0", "comment" => ""],
 			"deleted" => ["type" => "boolean", "not null" => "1", "default" => "0", "comment" => "item has been deleted"],
 			// User specific fields. Eventually they will move to user-item
-			"uid" => ["type" => "mediumint unsigned", "not null" => "1", "default" => "0", "relation" => ["user" => "uid"], "comment" => "Owner id which owns this copy of the item"],
+			"uid" => ["type" => "mediumint unsigned", "not null" => "1", "default" => "0", "foreign" => ["user" => "uid"], "comment" => "Owner id which owns this copy of the item"],
 			"contact-id" => ["type" => "int unsigned", "not null" => "1", "default" => "0", "relation" => ["contact" => "id"], "comment" => "contact.id"],
 			"wall" => ["type" => "boolean", "not null" => "1", "default" => "0", "comment" => "This item was posted to the wall of uid"],
 			"origin" => ["type" => "boolean", "not null" => "1", "default" => "0", "comment" => "item originated at this site"],
@@ -1008,7 +1010,7 @@ return [
 		"comment" => "Store OpenWebAuth token to verify contacts",
 		"fields" => [
 			"id" => ["type" => "int unsigned", "not null" => "1", "extra" => "auto_increment", "primary" => "1", "comment" => "sequential ID"],
-			"uid" => ["type" => "mediumint unsigned", "not null" => "1", "default" => "0", "relation" => ["user" => "uid"], "comment" => "User id - currently unused"],
+			"uid" => ["type" => "mediumint unsigned", "not null" => "1", "default" => "0", "foreign" => ["user" => "uid"], "comment" => "User id - currently unused"],
 			"type" => ["type" => "varchar(32)", "not null" => "1", "default" => "", "comment" => "Verify type"],
 			"token" => ["type" => "varchar(255)", "not null" => "1", "default" => "", "comment" => "A generated token"],
 			"meta" => ["type" => "varchar(255)", "not null" => "1", "default" => "", "comment" => ""],
@@ -1065,7 +1067,7 @@ return [
 		"comment" => "photo storage",
 		"fields" => [
 			"id" => ["type" => "int unsigned", "not null" => "1", "extra" => "auto_increment", "primary" => "1", "comment" => "sequential ID"],
-			"uid" => ["type" => "mediumint unsigned", "not null" => "1", "default" => "0", "relation" => ["user" => "uid"], "comment" => "Owner User id"],
+			"uid" => ["type" => "mediumint unsigned", "not null" => "1", "default" => "0", "foreign" => ["user" => "uid"], "comment" => "Owner User id"],
 			"contact-id" => ["type" => "int unsigned", "not null" => "1", "default" => "0", "foreign" => ["contact" => "id", "on delete" => "restrict"], "comment" => "contact.id"],
 			"guid" => ["type" => "char(16)", "not null" => "1", "default" => "", "comment" => "A unique identifier for this photo"],
 			"resource-id" => ["type" => "char(32)", "not null" => "1", "default" => "", "comment" => ""],
@@ -1105,13 +1107,14 @@ return [
 		"comment" => "post relation to categories",
 		"fields" => [
 			"uri-id" => ["type" => "int unsigned", "not null" => "1", "primary" => "1",  "foreign" => ["item-uri" => "id"], "comment" => "Id of the item-uri table entry that contains the item uri"],
-			"uid" => ["type" => "mediumint unsigned", "not null" => "1", "default" => "0", "primary" => "1", "relation" => ["user" => "uid"], "comment" => "User id"],
+			"uid" => ["type" => "mediumint unsigned", "not null" => "1", "default" => "0", "primary" => "1", "foreign" => ["user" => "uid"], "comment" => "User id"],
 			"type" => ["type" => "tinyint unsigned", "not null" => "1", "default" => "0", "primary" => "1", "comment" => ""],
 			"tid" => ["type" => "int unsigned", "not null" => "1", "default" => "0", "primary" => "1", "foreign" => ["tag" => "id", "on delete" => "restrict"], "comment" => ""],
 		],
 		"indexes" => [
 			"PRIMARY" => ["uri-id", "uid", "type", "tid"],
-			"uri-id" => ["tid"]
+			"uri-id" => ["tid"],
+			"uid" => ["uid"],
 		]
 	],
 	"post-delivery-data" => [
@@ -1168,6 +1171,25 @@ return [
 			"cid" => ["cid"]
 		]
 	],
+	"post-user" => [
+		"comment" => "User specific post data",
+		"fields" => [
+			"uri-id" => ["type" => "int unsigned", "not null" => "1", "primary" => "1", "foreign" => ["item-uri" => "id"], "comment" => "Id of the item-uri table entry that contains the item uri"],
+			"uid" => ["type" => "mediumint unsigned", "not null" => "1", "primary" => "1", "foreign" => ["user" => "uid"], "comment" => "Owner id which owns this copy of the item"],
+			"contact-id" => ["type" => "int unsigned", "not null" => "1", "default" => "0", "foreign" => ["contact" => "id"], "comment" => "contact.id"],
+			"unseen" => ["type" => "boolean", "not null" => "1", "default" => "1", "comment" => "post has not been seen"],
+			"hidden" => ["type" => "boolean", "not null" => "1", "default" => "0", "comment" => "Marker to hide the post from the user"],
+			"notification-type" => ["type" => "tinyint unsigned", "not null" => "1", "default" => "0", "comment" => ""],
+			"origin" => ["type" => "boolean", "not null" => "1", "default" => "0", "comment" => "item originated at this site"],
+			"psid" => ["type" => "int unsigned", "foreign" => ["permissionset" => "id", "on delete" => "restrict"], "comment" => "ID of the permission set of this post"],
+		],
+		"indexes" => [
+			"PRIMARY" => ["uid", "uri-id"],
+			"uri-id" => ["uri-id"],
+			"contact-id" => ["contact-id"],
+			"psid" => ["psid"],
+		],
+	],
 	"process" => [
 		"comment" => "Currently running system processes",
 		"fields" => [
@@ -1345,7 +1367,7 @@ return [
 			"iid" => ["type" => "int unsigned", "not null" => "1", "default" => "0", "primary" => "1", "foreign" => ["item" => "id"],
 				"comment" => "sequential ID"],
 			"uri-id" => ["type" => "int unsigned", "foreign" => ["item-uri" => "id"], "comment" => "Id of the item-uri table entry that contains the item uri"],
-			"uid" => ["type" => "mediumint unsigned", "not null" => "1", "default" => "0", "relation" => ["user" => "uid"], "comment" => "User id"],
+			"uid" => ["type" => "mediumint unsigned", "not null" => "1", "default" => "0", "foreign" => ["user" => "uid"], "comment" => "User id"],
 			"contact-id" => ["type" => "int unsigned", "not null" => "1", "default" => "0", "relation" => ["contact" => "id"], "comment" => ""],
 			"owner-id" => ["type" => "int unsigned", "not null" => "1", "default" => "0", "relation" => ["contact" => "id"], "comment" => "Item owner"],
 			"author-id" => ["type" => "int unsigned", "not null" => "1", "default" => "0", "relation" => ["contact" => "id"], "comment" => "Item author"],
diff --git a/update.php b/update.php
index 460fad885..3544275c0 100644
--- a/update.php
+++ b/update.php
@@ -758,3 +758,41 @@ function update_1375()
 
 	return Update::SUCCESS;
 }
+
+function pre_update_1376()
+{
+	// Insert a user with uid=0
+	DBStructure::checkInitialValues();
+
+	if (!DBA::e("DELETE FROM `item` WHERE NOT `uid` IN (SELECT `uid` FROM `user`)")) {
+		return Update::FAILED;
+	}
+
+	if (!DBA::e("DELETE FROM `event` WHERE NOT `uid` IN (SELECT `uid` FROM `user`)")) {
+		return Update::FAILED;
+	}
+
+	if (!DBA::e("DELETE FROM `thread` WHERE NOT `uid` IN (SELECT `uid` FROM `user`)")) {
+		return Update::FAILED;
+	}
+
+	if (!DBA::e("DELETE FROM `permissionset` WHERE NOT `uid` IN (SELECT `uid` FROM `user`)")) {
+		return Update::FAILED;
+	}
+
+	if (!DBA::e("DELETE FROM `openwebauth-token` WHERE NOT `uid` IN (SELECT `uid` FROM `user`)")) {
+		return Update::FAILED;
+	}
+
+	if (!DBA::e("DELETE FROM `post-category` WHERE NOT `uid` IN (SELECT `uid` FROM `user`)")) {
+		return Update::FAILED;
+	}
+
+	if (!DBA::e("DELETE FROM `contact` WHERE NOT `uid` IN (SELECT `uid` FROM `user`)")) {
+		return Update::FAILED;
+	}
+
+	Photo::delete(["NOT `uid` IN (SELECT `uid` FROM `user`)"]);
+
+	return Update::SUCCESS;
+}