diff --git a/database.sql b/database.sql
index 6c16deb30d..979320cc7c 100644
--- a/database.sql
+++ b/database.sql
@@ -2034,7 +2034,7 @@ CREATE TABLE IF NOT EXISTS `worker-ipc` (
 -- VIEW application-view
 --
 DROP VIEW IF EXISTS `application-view`;
-CREATE VIEW `application-view` AS SELECT
+CREATE VIEW `application-view` AS SELECT 
 	`application`.`id` AS `id`,
 	`application-token`.`uid` AS `uid`,
 	`application`.`name` AS `name`,
@@ -2058,7 +2058,7 @@ CREATE VIEW `application-view` AS SELECT
 -- VIEW circle-member-view
 --
 DROP VIEW IF EXISTS `circle-member-view`;
-CREATE VIEW `circle-member-view` AS SELECT
+CREATE VIEW `circle-member-view` AS SELECT 
 	`group_member`.`id` AS `id`,
 	`group`.`uid` AS `uid`,
 	`group_member`.`contact-id` AS `contact-id`,
@@ -2089,7 +2089,7 @@ CREATE VIEW `circle-member-view` AS SELECT
 -- VIEW post-counts-view
 --
 DROP VIEW IF EXISTS `post-counts-view`;
-CREATE VIEW `post-counts-view` AS SELECT
+CREATE VIEW `post-counts-view` AS SELECT 
 	`post-counts`.`uri-id` AS `uri-id`,
 	`post-counts`.`vid` AS `vid`,
 	`verb`.`name` AS `verb`,
@@ -2103,7 +2103,7 @@ CREATE VIEW `post-counts-view` AS SELECT
 -- VIEW post-engagement-user-view
 --
 DROP VIEW IF EXISTS `post-engagement-user-view`;
-CREATE VIEW `post-engagement-user-view` AS SELECT
+CREATE VIEW `post-engagement-user-view` AS SELECT 
 	`post-thread-user`.`uid` AS `uid`,
 	`post-engagement`.`uri-id` AS `uri-id`,
 	`post-engagement`.`owner-id` AS `owner-id`,
@@ -2135,7 +2135,7 @@ CREATE VIEW `post-engagement-user-view` AS SELECT
 -- VIEW post-timeline-view
 --
 DROP VIEW IF EXISTS `post-timeline-view`;
-CREATE VIEW `post-timeline-view` AS SELECT
+CREATE VIEW `post-timeline-view` AS SELECT 
 	`post-user`.`uid` AS `uid`,
 	`post-user`.`uri-id` AS `uri-id`,
 	`post-user`.`gravity` AS `gravity`,
@@ -2180,7 +2180,7 @@ CREATE VIEW `post-timeline-view` AS SELECT
 -- VIEW post-timeline-origin-view
 --
 DROP VIEW IF EXISTS `post-timeline-origin-view`;
-CREATE VIEW `post-timeline-origin-view` AS SELECT
+CREATE VIEW `post-timeline-origin-view` AS SELECT 
 	`post-origin`.`uid` AS `uid`,
 	`post-origin`.`uri-id` AS `uri-id`,
 	`post-origin`.`gravity` AS `gravity`,
@@ -2226,7 +2226,7 @@ CREATE VIEW `post-timeline-origin-view` AS SELECT
 -- VIEW post-searchindex-user-view
 --
 DROP VIEW IF EXISTS `post-searchindex-user-view`;
-CREATE VIEW `post-searchindex-user-view` AS SELECT
+CREATE VIEW `post-searchindex-user-view` AS SELECT 
 	`post-thread-user`.`uid` AS `uid`,
 	`post-searchindex`.`uri-id` AS `uri-id`,
 	`post-searchindex`.`owner-id` AS `owner-id`,
@@ -2258,7 +2258,7 @@ CREATE VIEW `post-searchindex-user-view` AS SELECT
 -- VIEW post-origin-view
 --
 DROP VIEW IF EXISTS `post-origin-view`;
-CREATE VIEW `post-origin-view` AS SELECT
+CREATE VIEW `post-origin-view` AS SELECT 
 	`post-origin`.`id` AS `id`,
 	`post-origin`.`id` AS `post-user-id`,
 	`post-origin`.`uid` AS `uid`,
@@ -2446,7 +2446,7 @@ CREATE VIEW `post-origin-view` AS SELECT
 -- VIEW post-thread-origin-view
 --
 DROP VIEW IF EXISTS `post-thread-origin-view`;
-CREATE VIEW `post-thread-origin-view` AS SELECT
+CREATE VIEW `post-thread-origin-view` AS SELECT 
 	`post-origin`.`id` AS `id`,
 	`post-origin`.`id` AS `post-user-id`,
 	`post-origin`.`uid` AS `uid`,
@@ -2632,7 +2632,7 @@ CREATE VIEW `post-thread-origin-view` AS SELECT
 -- VIEW post-user-view
 --
 DROP VIEW IF EXISTS `post-user-view`;
-CREATE VIEW `post-user-view` AS SELECT
+CREATE VIEW `post-user-view` AS SELECT 
 	`post-user`.`id` AS `id`,
 	`post-user`.`id` AS `post-user-id`,
 	`post-user`.`uid` AS `uid`,
@@ -2819,7 +2819,7 @@ CREATE VIEW `post-user-view` AS SELECT
 -- VIEW post-thread-user-view
 --
 DROP VIEW IF EXISTS `post-thread-user-view`;
-CREATE VIEW `post-thread-user-view` AS SELECT
+CREATE VIEW `post-thread-user-view` AS SELECT 
 	`post-user`.`id` AS `id`,
 	`post-user`.`id` AS `post-user-id`,
 	`post-thread-user`.`uid` AS `uid`,
@@ -3004,7 +3004,7 @@ CREATE VIEW `post-thread-user-view` AS SELECT
 -- VIEW post-view
 --
 DROP VIEW IF EXISTS `post-view`;
-CREATE VIEW `post-view` AS SELECT
+CREATE VIEW `post-view` AS SELECT 
 	`item-uri`.`uri` AS `uri`,
 	`post`.`uri-id` AS `uri-id`,
 	`parent-item-uri`.`uri` AS `parent-uri`,
@@ -3151,7 +3151,7 @@ CREATE VIEW `post-view` AS SELECT
 -- VIEW post-thread-view
 --
 DROP VIEW IF EXISTS `post-thread-view`;
-CREATE VIEW `post-thread-view` AS SELECT
+CREATE VIEW `post-thread-view` AS SELECT 
 	`item-uri`.`uri` AS `uri`,
 	`post-thread`.`uri-id` AS `uri-id`,
 	`parent-item-uri`.`uri` AS `parent-uri`,
@@ -3299,7 +3299,7 @@ CREATE VIEW `post-thread-view` AS SELECT
 -- VIEW category-view
 --
 DROP VIEW IF EXISTS `category-view`;
-CREATE VIEW `category-view` AS SELECT
+CREATE VIEW `category-view` AS SELECT 
 	`post-category`.`uri-id` AS `uri-id`,
 	`post-category`.`uid` AS `uid`,
 	`post-category`.`type` AS `type`,
@@ -3313,7 +3313,7 @@ CREATE VIEW `category-view` AS SELECT
 -- VIEW collection-view
 --
 DROP VIEW IF EXISTS `collection-view`;
-CREATE VIEW `collection-view` AS SELECT
+CREATE VIEW `collection-view` AS SELECT 
 	`post-collection`.`uri-id` AS `uri-id`,
 	`post-collection`.`type` AS `type`,
 	`post-collection`.`author-id` AS `cid`,
@@ -3334,7 +3334,7 @@ CREATE VIEW `collection-view` AS SELECT
 -- VIEW media-view
 --
 DROP VIEW IF EXISTS `media-view`;
-CREATE VIEW `media-view` AS SELECT
+CREATE VIEW `media-view` AS SELECT 
 	`post-media`.`uri-id` AS `uri-id`,
 	`post-media`.`type` AS `type`,
 	`post`.`received` AS `received`,
@@ -3352,7 +3352,7 @@ CREATE VIEW `media-view` AS SELECT
 -- VIEW tag-view
 --
 DROP VIEW IF EXISTS `tag-view`;
-CREATE VIEW `tag-view` AS SELECT
+CREATE VIEW `tag-view` AS SELECT 
 	`post-tag`.`uri-id` AS `uri-id`,
 	`post-tag`.`type` AS `type`,
 	`post-tag`.`tid` AS `tid`,
@@ -3368,7 +3368,7 @@ CREATE VIEW `tag-view` AS SELECT
 -- VIEW network-thread-view
 --
 DROP VIEW IF EXISTS `network-thread-view`;
-CREATE VIEW `network-thread-view` AS SELECT
+CREATE VIEW `network-thread-view` AS SELECT 
 	`post-thread-user`.`uri-id` AS `uri-id`,
 	`post-thread-user`.`post-user-id` AS `parent`,
 	`post-thread-user`.`received` AS `received`,
@@ -3396,7 +3396,7 @@ CREATE VIEW `network-thread-view` AS SELECT
 -- VIEW network-thread-circle-view
 --
 DROP VIEW IF EXISTS `network-thread-circle-view`;
-CREATE VIEW `network-thread-circle-view` AS SELECT
+CREATE VIEW `network-thread-circle-view` AS SELECT 
 	`post-thread-user`.`uri-id` AS `uri-id`,
 	`post-thread-user`.`post-user-id` AS `parent`,
 	`post-thread-user`.`received` AS `received`,
@@ -3424,7 +3424,7 @@ CREATE VIEW `network-thread-circle-view` AS SELECT
 -- VIEW owner-view
 --
 DROP VIEW IF EXISTS `owner-view`;
-CREATE VIEW `owner-view` AS SELECT
+CREATE VIEW `owner-view` AS SELECT 
 	`contact`.`id` AS `id`,
 	`contact`.`uid` AS `uid`,
 	`contact`.`created` AS `created`,
@@ -3552,7 +3552,7 @@ CREATE VIEW `owner-view` AS SELECT
 -- VIEW account-view
 --
 DROP VIEW IF EXISTS `account-view`;
-CREATE VIEW `account-view` AS SELECT
+CREATE VIEW `account-view` AS SELECT 
 	`contact`.`id` AS `id`,
 	`contact`.`url` AS `url`,
 	`contact`.`nurl` AS `nurl`,
@@ -3640,7 +3640,7 @@ CREATE VIEW `account-view` AS SELECT
 -- VIEW account-user-view
 --
 DROP VIEW IF EXISTS `account-user-view`;
-CREATE VIEW `account-user-view` AS SELECT
+CREATE VIEW `account-user-view` AS SELECT 
 	`ucontact`.`id` AS `id`,
 	`contact`.`id` AS `pid`,
 	`ucontact`.`uid` AS `uid`,
@@ -3746,7 +3746,7 @@ CREATE VIEW `account-user-view` AS SELECT
 -- VIEW pending-view
 --
 DROP VIEW IF EXISTS `pending-view`;
-CREATE VIEW `pending-view` AS SELECT
+CREATE VIEW `pending-view` AS SELECT 
 	`register`.`id` AS `id`,
 	`register`.`hash` AS `hash`,
 	`register`.`created` AS `created`,
@@ -3768,7 +3768,7 @@ CREATE VIEW `pending-view` AS SELECT
 -- VIEW tag-search-view
 --
 DROP VIEW IF EXISTS `tag-search-view`;
-CREATE VIEW `tag-search-view` AS SELECT
+CREATE VIEW `tag-search-view` AS SELECT 
 	`post-tag`.`uri-id` AS `uri-id`,
 	`post-user`.`uid` AS `uid`,
 	`post-user`.`id` AS `iid`,
@@ -3790,7 +3790,7 @@ CREATE VIEW `tag-search-view` AS SELECT
 -- VIEW workerqueue-view
 --
 DROP VIEW IF EXISTS `workerqueue-view`;
-CREATE VIEW `workerqueue-view` AS SELECT
+CREATE VIEW `workerqueue-view` AS SELECT 
 	`process`.`pid` AS `pid`,
 	`workerqueue`.`priority` AS `priority`
 	FROM `process`
@@ -3801,7 +3801,7 @@ CREATE VIEW `workerqueue-view` AS SELECT
 -- VIEW profile_field-view
 --
 DROP VIEW IF EXISTS `profile_field-view`;
-CREATE VIEW `profile_field-view` AS SELECT
+CREATE VIEW `profile_field-view` AS SELECT 
 	`profile_field`.`id` AS `id`,
 	`profile_field`.`uid` AS `uid`,
 	`profile_field`.`label` AS `label`,
@@ -3821,7 +3821,7 @@ CREATE VIEW `profile_field-view` AS SELECT
 -- VIEW diaspora-contact-view
 --
 DROP VIEW IF EXISTS `diaspora-contact-view`;
-CREATE VIEW `diaspora-contact-view` AS SELECT
+CREATE VIEW `diaspora-contact-view` AS SELECT 
 	`diaspora-contact`.`uri-id` AS `uri-id`,
 	`item-uri`.`uri` AS `url`,
 	`item-uri`.`guid` AS `guid`,
diff --git a/src/DI.php b/src/DI.php
index a984bc934f..99d6e1012d 100644
--- a/src/DI.php
+++ b/src/DI.php
@@ -66,7 +66,7 @@ abstract class DI
 	public static function setCompositeRootDependencyByHand()
 	{
 		$database = static::dba();
-		$database->setDependency(static::config(), static::profiler(), static::logger());
+		$database->setDependency(static::config(), static::profiler(), static::logger(), static::lock());
 	}
 
 	/**
diff --git a/src/Database/DBA.php b/src/Database/DBA.php
index d5e5a7e59b..afbb5e130d 100644
--- a/src/Database/DBA.php
+++ b/src/Database/DBA.php
@@ -21,6 +21,7 @@
 
 namespace Friendica\Database;
 
+use Friendica\Core\Lock\Exception\LockPersistenceException;
 use Friendica\DI;
 use mysqli;
 use mysqli_result;
@@ -823,6 +824,27 @@ class DBA
 		return DI::dba()->optimizeTable($table);
 	}
 
+	/**
+	 * Acquire a lock to prevent a table optimization
+	 *
+	 * @return bool 
+	 * @throws LockPersistenceException 
+	 */
+	public static function acquireOptimizeLock(): bool
+	{
+		return DI::dba()->acquireOptimizeLock();
+	}
+
+	/**
+	 * Release the table optimization lock
+	 * @return bool 
+	 * @throws LockPersistenceException 
+	 */
+	public static function releaseOptimizeLock(): bool
+	{
+		return DI::dba()->releaseOptimizeLock();
+	}
+
 	/**
 	 * Kill sleeping database processes
 	 */
diff --git a/src/Database/Database.php b/src/Database/Database.php
index c296683d2b..2691495850 100644
--- a/src/Database/Database.php
+++ b/src/Database/Database.php
@@ -22,6 +22,8 @@
 namespace Friendica\Database;
 
 use Friendica\Core\Config\Capability\IManageConfigValues;
+use Friendica\Core\Lock\Capability\ICanLock;
+use Friendica\Core\Lock\Exception\LockPersistenceException;
 use Friendica\Core\System;
 use Friendica\Database\Definition\DbaDefinition;
 use Friendica\Database\Definition\ViewDefinition;
@@ -50,6 +52,8 @@ class Database
 	const INSERT_UPDATE  = 1;
 	const INSERT_IGNORE  = 2;
 
+	const LOCK_OPTIMIZE = 'database::optimize_tables';
+
 	protected $connected = false;
 
 	/**
@@ -64,6 +68,11 @@ class Database
 	 * @var LoggerInterface
 	 */
 	protected $logger = null;
+	/**
+	 * @var ICanLock
+	 */
+	protected $syslock = null;
+
 	protected $server_info = '';
 	/** @var PDO|mysqli */
 	protected $connection;
@@ -106,11 +115,12 @@ class Database
 	 *
 	 * @todo Make this method obsolete - use a clean pattern instead ...
 	 */
-	public function setDependency(IManageConfigValues $config, Profiler $profiler, LoggerInterface $logger)
+	public function setDependency(IManageConfigValues $config, Profiler $profiler, LoggerInterface $logger, ICanLock $lock)
 	{
 		$this->logger   = $logger;
 		$this->profiler = $profiler;
 		$this->config   = $config;
+		$this->syslock  = $lock;
 	}
 
 	/**
@@ -1755,7 +1765,42 @@ class Database
 	 */
 	public function optimizeTable(string $table): bool
 	{
-		return $this->e("OPTIMIZE TABLE " . DBA::buildTableString([$table])) !== false;
+		if ($this->syslock->isLocked(self::LOCK_OPTIMIZE)) {
+			$this->logger->info('Optimization is locked');
+			return false;
+		}
+
+		if (!$this->acquireOptimizeLock()) {
+			return false;
+		}
+
+		$result = $this->e("OPTIMIZE TABLE " . DBA::buildTableString([$table])) !== false;
+
+		$this->releaseOptimizeLock();
+
+		return $result;
+	}
+
+	/**
+	 * Acquire a lock to prevent a table optimization
+	 *
+	 * @return bool 
+	 * @throws LockPersistenceException 
+	 */
+	public function acquireOptimizeLock(): bool
+	{
+		return $this->syslock->acquire(self::LOCK_OPTIMIZE, 0);
+	}
+
+	/**
+	 * Release the table optimization lock
+	 *
+	 * @return bool 
+	 * @throws LockPersistenceException 
+	 */
+	public function releaseOptimizeLock(): bool
+	{
+		return $this->syslock->release(self::LOCK_OPTIMIZE);
 	}
 
 	/**
diff --git a/src/Worker/ExpirePosts.php b/src/Worker/ExpirePosts.php
index 3ff58a08c4..3e4958c6a2 100644
--- a/src/Worker/ExpirePosts.php
+++ b/src/Worker/ExpirePosts.php
@@ -40,6 +40,11 @@ class ExpirePosts
 	 */
 	public static function execute()
 	{
+		if (!DBA::acquireOptimizeLock()) {
+			Logger::warning('Lock could not be acquired');
+			return;
+		}
+
 		self::deleteExpiredOriginPosts();
 
 		self::deleteOrphanedEntries();
@@ -52,6 +57,8 @@ class ExpirePosts
 			self::addMissingEntries();
 		}
 
+		DBA::releaseOptimizeLock();
+
 		// Set the expiry for origin posts
 		Worker::add(Worker::PRIORITY_LOW, 'Expire');
 
@@ -69,15 +76,22 @@ class ExpirePosts
 		Logger::notice('Delete expired posts');
 		// physically remove anything that has been deleted for more than two months
 		$condition = ["`gravity` = ? AND `deleted` AND `changed` < ?", Item::GRAVITY_PARENT, DateTimeFormat::utc('now - 60 days')];
-		$rows = Post::select(['guid', 'uri-id', 'uid'],  $condition);
-		while ($row = Post::fetch($rows)) {
-			Logger::info('Delete expired item', ['uri-id' => $row['uri-id'], 'guid' => $row['guid']]);
-			Post\User::delete(['parent-uri-id' => $row['uri-id'], 'uid' => $row['uid']]);
-			Post\Origin::delete(['parent-uri-id' => $row['uri-id'], 'uid' => $row['uid']]);
-		}
-		DBA::close($rows);
-
-		Logger::notice('Delete expired posts - done');
+		$pass = 0;
+		do {
+			++$pass;
+			$rows = Post::select(['guid', 'uri-id', 'uid'],  $condition, ['limit' => 100]);
+			$affected_count = 0;
+			while ($row = Post::fetch($rows)) {
+				Logger::info('Delete expired item', ['pass' => $pass, 'uri-id' => $row['uri-id'], 'guid' => $row['guid']]);
+				Post\User::delete(['parent-uri-id' => $row['uri-id'], 'uid' => $row['uid']]);
+				$affected_count += DBA::affectedRows();
+				Post\Origin::delete(['parent-uri-id' => $row['uri-id'], 'uid' => $row['uid']]);
+				$affected_count += DBA::affectedRows();
+			}
+			DBA::close($rows);
+			DBA::commit();
+			Logger::notice('Delete expired posts - done', ['pass' => $pass, 'rows' => $affected_count]);
+		} while ($affected_count);
 	}
 
 	/**
@@ -106,6 +120,7 @@ class ExpirePosts
 				$affected_count += DBA::affectedRows();
 			}
 			DBA::close($uris);
+			DBA::commit();
 			Logger::notice('Orphaned entries deleted', ['table' => $table, 'rows' => $affected_count]);
 		}
 		Logger::notice('Delete orphaned entries - done');
@@ -172,14 +187,18 @@ class ExpirePosts
 	{
 		// We have to avoid deleting newly created "item-uri" entries.
 		// So we fetch a post that had been stored yesterday and only delete older ones.
-		$item = Post::selectFirstThread(['uri-id'], ["`uid` = ? AND `received` < ?", 0, DateTimeFormat::utc('now - 1 day')],
-			['order' => ['received' => true]]);
+		$item = Post::selectFirstThread(
+			['uri-id'],
+			["`uid` = ? AND `received` < ?", 0, DateTimeFormat::utc('now - 1 day')],
+			['order' => ['received' => true]]
+		);
 		if (empty($item['uri-id'])) {
 			Logger::warning('No item with uri-id found - we better quit here');
 			return;
 		}
 		Logger::notice('Start collecting orphaned URI-ID', ['last-id' => $item['uri-id']]);
-		$uris = DBA::select('item-uri', ['id'], ["`id` < ?
+		$condition = [
+			"`id` < ?
 			AND NOT EXISTS(SELECT `uri-id` FROM `post-user` WHERE `uri-id` = `item-uri`.`id`)
 			AND NOT EXISTS(SELECT `parent-uri-id` FROM `post-user` WHERE `parent-uri-id` = `item-uri`.`id`)
 			AND NOT EXISTS(SELECT `thr-parent-id` FROM `post-user` WHERE `thr-parent-id` = `item-uri`.`id`)
@@ -195,18 +214,24 @@ class ExpirePosts
 			AND NOT EXISTS(SELECT `uri-id` FROM `post-delivery` WHERE `uri-id` = `item-uri`.`id`)
 			AND NOT EXISTS(SELECT `uri-id` FROM `post-delivery` WHERE `inbox-id` = `item-uri`.`id`)
 			AND NOT EXISTS(SELECT `parent-uri-id` FROM `mail` WHERE `parent-uri-id` = `item-uri`.`id`)
-			AND NOT EXISTS(SELECT `thr-parent-id` FROM `mail` WHERE `thr-parent-id` = `item-uri`.`id`)", $item['uri-id']]);
-
-		Logger::notice('Start deleting orphaned URI-ID', ['last-id' => $item['uri-id']]);
-		$affected_count = 0;
-		while ($rows = DBA::toArray($uris, false, 100)) {
-			$ids = array_column($rows, 'id');
-			DBA::delete('item-uri', ['id' => $ids]);
-			$affected_count += DBA::affectedRows();
-			Logger::info('Deleted', ['rows' => $affected_count]);
-		}
-		DBA::close($uris);
-		Logger::notice('Orphaned URI-ID entries removed', ['rows' => $affected_count]);
+			AND NOT EXISTS(SELECT `thr-parent-id` FROM `mail` WHERE `thr-parent-id` = `item-uri`.`id`)", $item['uri-id']
+		];
+		$pass = 0;
+		do {
+			++$pass;
+			$uris = DBA::select('item-uri', ['id'], $condition, ['limit' => 1000]);
+			Logger::notice('Start deleting orphaned URI-ID', ['pass' => $pass, 'last-id' => $item['uri-id']]);
+			$affected_count = 0;
+			while ($rows = DBA::toArray($uris, false, 100)) {
+				$ids = array_column($rows, 'id');
+				DBA::delete('item-uri', ['id' => $ids]);
+				$affected_count += DBA::affectedRows();
+				Logger::info('Deleted', ['pass' => $pass, 'rows' => $affected_count]);
+			}
+			DBA::close($uris);
+			DBA::commit();
+			Logger::notice('Orphaned URI-ID entries removed', ['pass' => $pass, 'rows' => $affected_count]);
+		} while ($affected_count);
 	}
 
 	/**
@@ -227,55 +252,68 @@ class ExpirePosts
 
 		if (!empty($expire_days)) {
 			Logger::notice('Start collecting expired threads', ['expiry_days' => $expire_days]);
-			$uris = DBA::select('item-uri', ['id'], ["`id` IN
-				(SELECT `uri-id` FROM `post-thread` WHERE `received` < ?
-					AND NOT `uri-id` IN (SELECT `uri-id` FROM `post-thread-user`
-						WHERE (`mention` OR `starred` OR `wall`) AND `uri-id` = `post-thread`.`uri-id`)
-					AND NOT `uri-id` IN (SELECT `uri-id` FROM `post-category`
-						WHERE `uri-id` = `post-thread`.`uri-id`)
-					AND NOT `uri-id` IN (SELECT `uri-id` FROM `post-collection`
-						WHERE `uri-id` = `post-thread`.`uri-id`)
-					AND NOT `uri-id` IN (SELECT `uri-id` FROM `post-media`
-						WHERE `uri-id` = `post-thread`.`uri-id`)
-					AND NOT `uri-id` IN (SELECT `parent-uri-id` FROM `post-user` INNER JOIN `contact` ON `contact`.`id` = `contact-id` AND `notify_new_posts`
-						WHERE `parent-uri-id` = `post-thread`.`uri-id`)
-					AND NOT `uri-id` IN (SELECT `parent-uri-id` FROM `post-user`
-						WHERE (`origin` OR `event-id` != 0 OR `post-type` = ?) AND `parent-uri-id` = `post-thread`.`uri-id`)
-					AND NOT `uri-id` IN (SELECT `uri-id` FROM `post-content`
-						WHERE `resource-id` != 0 AND `uri-id` = `post-thread`.`uri-id`))",
-			    DateTimeFormat::utc('now - ' . (int)$expire_days . ' days'), Item::PT_PERSONAL_NOTE]);
+			$condition = [
+				"`id` IN (SELECT `uri-id` FROM `post-thread` WHERE `received` < ?
+				AND NOT `uri-id` IN (SELECT `uri-id` FROM `post-thread-user`
+					WHERE (`mention` OR `starred` OR `wall`) AND `uri-id` = `post-thread`.`uri-id`)
+				AND NOT `uri-id` IN (SELECT `uri-id` FROM `post-category`
+					WHERE `uri-id` = `post-thread`.`uri-id`)
+				AND NOT `uri-id` IN (SELECT `uri-id` FROM `post-collection`
+					WHERE `uri-id` = `post-thread`.`uri-id`)
+				AND NOT `uri-id` IN (SELECT `uri-id` FROM `post-media`
+					WHERE `uri-id` = `post-thread`.`uri-id`)
+				AND NOT `uri-id` IN (SELECT `parent-uri-id` FROM `post-user` INNER JOIN `contact` ON `contact`.`id` = `contact-id` AND `notify_new_posts`
+					WHERE `parent-uri-id` = `post-thread`.`uri-id`)
+				AND NOT `uri-id` IN (SELECT `parent-uri-id` FROM `post-user`
+					WHERE (`origin` OR `event-id` != 0 OR `post-type` = ?) AND `parent-uri-id` = `post-thread`.`uri-id`)
+				AND NOT `uri-id` IN (SELECT `uri-id` FROM `post-content`
+					WHERE `resource-id` != 0 AND `uri-id` = `post-thread`.`uri-id`))",
+				DateTimeFormat::utc('now - ' . (int)$expire_days . ' days'), Item::PT_PERSONAL_NOTE
+			];
+			$pass = 0;
+			do {
+				++$pass;
+				$uris = DBA::select('item-uri', ['id'], $condition, ['limit' => 100]);
 
-			Logger::notice('Start deleting expired threads');
-			$affected_count = 0;
-			while ($rows = DBA::toArray($uris, false, 100)) {
-				$ids = array_column($rows, 'id');
-				DBA::delete('item-uri', ['id' => $ids]);
-				$affected_count += DBA::affectedRows();
-			}
-			DBA::close($uris);
-
-			Logger::notice('Deleted expired threads', ['rows' => $affected_count]);
+				Logger::notice('Start deleting expired threads', ['pass' => $pass]);
+				$affected_count = 0;
+				while ($rows = DBA::toArray($uris, false, 100)) {
+					$ids = array_column($rows, 'id');
+					DBA::delete('item-uri', ['id' => $ids]);
+					$affected_count += DBA::affectedRows();
+				}
+				DBA::close($uris);
+				DBA::commit();
+				Logger::notice('Deleted expired threads', ['pass' => $pass, 'rows' => $affected_count]);
+			} while ($affected_count);
 		}
 
 		if (!empty($expire_days_unclaimed)) {
 			Logger::notice('Start collecting unclaimed public items', ['expiry_days' => $expire_days_unclaimed]);
-			$uris = DBA::select('item-uri', ['id'], ["`id` IN
-				(SELECT `uri-id` FROM `post-user` WHERE `gravity` = ? AND `uid` = ? AND `received` < ?
-					AND NOT `uri-id` IN (SELECT `parent-uri-id` FROM `post-user` AS `i` WHERE `i`.`uid` != ?
-						AND `i`.`parent-uri-id` = `post-user`.`uri-id`)
-					AND NOT `uri-id` IN (SELECT `parent-uri-id` FROM `post-user` AS `i` WHERE `i`.`uid` = ?
-						AND `i`.`parent-uri-id` = `post-user`.`uri-id` AND `i`.`received` > ?))",
-				Item::GRAVITY_PARENT, 0, DateTimeFormat::utc('now - ' . (int)$expire_days_unclaimed . ' days'), 0, 0, DateTimeFormat::utc('now - ' . (int)$expire_days_unclaimed . ' days')]);
+			$condition = [
+				"`id` IN (SELECT `uri-id` FROM `post-user` WHERE `gravity` = ? AND `uid` = ? AND `received` < ?
+				AND NOT `uri-id` IN (SELECT `parent-uri-id` FROM `post-user` AS `i` WHERE `i`.`uid` != ?
+					AND `i`.`parent-uri-id` = `post-user`.`uri-id`)
+				AND NOT `uri-id` IN (SELECT `parent-uri-id` FROM `post-user` AS `i` WHERE `i`.`uid` = ?
+					AND `i`.`parent-uri-id` = `post-user`.`uri-id` AND `i`.`received` > ?))",
+				Item::GRAVITY_PARENT, 0, DateTimeFormat::utc('now - ' . (int)$expire_days_unclaimed . ' days'), 0, 0, DateTimeFormat::utc('now - ' . (int)$expire_days_unclaimed . ' days')
+			];
+			$pass = 0;
+			do {
+				++$pass;
+				$uris = DBA::select('item-uri', ['id'], $condition, ['limit' => 100]);
 
-			Logger::notice('Start deleting unclaimed public items');
-			$affected_count = 0;
-			while ($rows = DBA::toArray($uris, false, 100)) {
-				$ids = array_column($rows, 'id');
-				DBA::delete('item-uri', ['id' => $ids]);
-				$affected_count += DBA::affectedRows();
-			}
-			DBA::close($uris);
-			Logger::notice('Deleted unclaimed public items', ['rows' => $affected_count]);
+				Logger::notice('Start deleting unclaimed public items', ['pass' => $pass]);
+				$affected_count = 0;
+				while ($rows = DBA::toArray($uris, false, 100)) {
+					$ids = array_column($rows, 'id');
+					DBA::delete('item-uri', ['id' => $ids]);
+					$affected_count += DBA::affectedRows();
+				}
+				DBA::close($uris);
+				DBA::commit();
+				Logger::notice('Deleted unclaimed public items', ['pass' => $pass, 'rows' => $affected_count]);
+			} while ($affected_count);
 		}
 	}
 }