diff --git a/lib/Db/MessageMapper.php b/lib/Db/MessageMapper.php
index 1d80e55049..6dd1fda24d 100644
--- a/lib/Db/MessageMapper.php
+++ b/lib/Db/MessageMapper.php
@@ -50,6 +50,8 @@ class MessageMapper extends QBMapper {
 
 	use TTransactional;
 
+	public const ORACLE_MAX_CHUNK_SIZE = 1000;
+
 	/** @var ITimeFactory */
 	private $timeFactory;
 
@@ -182,7 +184,7 @@ public function findUidsForIds(Mailbox $mailbox, array $ids) {
 		return array_flat_map(function (array $chunk) use ($query) {
 			$query->setParameter('ids', $chunk, IQueryBuilder::PARAM_INT_ARRAY);
 			return $this->findUids($query);
-		}, array_chunk($ids, 1000));
+		}, array_chunk($ids, self::ORACLE_MAX_CHUNK_SIZE));
 	}
 
 	/**
@@ -481,7 +483,7 @@ public function updateBulk(Account $account, bool $permflagsEnabled, Message ...
 						$queryTrue->expr()->eq('mailbox_id', $queryTrue->createNamedParameter($mailboxId, IQueryBuilder::PARAM_INT)),
 						$queryTrue->expr()->eq($flag, $queryTrue->createNamedParameter(0, IQueryBuilder::PARAM_INT))
 					));
-				foreach (array_chunk($updateData[$flag . '_true'], 1000) as $chunk) {
+				foreach (array_chunk($updateData[$flag . '_true'], self::ORACLE_MAX_CHUNK_SIZE) as $chunk) {
 					$queryTrue->setParameter('uids', $chunk, IQueryBuilder::PARAM_INT_ARRAY);
 					$queryTrue->executeStatement();
 				}
@@ -495,7 +497,7 @@ public function updateBulk(Account $account, bool $permflagsEnabled, Message ...
 						$queryFalse->expr()->eq('mailbox_id', $queryFalse->createNamedParameter($mailboxId, IQueryBuilder::PARAM_INT)),
 						$queryFalse->expr()->eq($flag, $queryFalse->createNamedParameter(1, IQueryBuilder::PARAM_INT))
 					));
-				foreach (array_chunk($updateData[$flag . '_false'], 1000) as $chunk) {
+				foreach (array_chunk($updateData[$flag . '_false'], self::ORACLE_MAX_CHUNK_SIZE) as $chunk) {
 					$queryFalse->setParameter('uids', $chunk, IQueryBuilder::PARAM_INT_ARRAY);
 					$queryFalse->executeStatement();
 				}
@@ -695,7 +697,7 @@ public function deleteAll(Mailbox $mailbox): void {
 		$deleteRecipientsQuery->delete('mail_recipients')
 			->where($deleteRecipientsQuery->expr()->in('message_id', $deleteRecipientsQuery->createParameter('ids')));
 
-		foreach (array_chunk($messageIds, 1000) as $chunk) {
+		foreach (array_chunk($messageIds, self::ORACLE_MAX_CHUNK_SIZE) as $chunk) {
 			// delete all related recipient entries
 			$deleteRecipientsQuery->setParameter('ids', $chunk, IQueryBuilder::PARAM_INT_ARRAY);
 			$deleteRecipientsQuery->executeStatement();
@@ -729,7 +731,7 @@ public function deleteByUid(Mailbox $mailbox, int ...$uids): void {
 				$deleteMessagesQuery->expr()->in('id', $deleteMessagesQuery->createParameter('ids')),
 			);
 
-		foreach (array_chunk($uids, 1000) as $chunk) {
+		foreach (array_chunk($uids, self::ORACLE_MAX_CHUNK_SIZE) as $chunk) {
 			$this->atomic(function () use ($selectMessageIdsQuery, $deleteRecipientsQuery, $deleteMessagesQuery, $chunk) {
 				$selectMessageIdsQuery->setParameter('uids', $chunk, IQueryBuilder::PARAM_INT_ARRAY);
 				$selectResult = $selectMessageIdsQuery->executeQuery();
@@ -997,7 +999,7 @@ public function findIdsByQuery(Mailbox $mailbox, SearchQuery $query, string $sor
 			return array_flat_map(function (array $chunk) use ($qb, $select) {
 				$qb->setParameter('uids', $chunk, IQueryBuilder::PARAM_INT_ARRAY);
 				return array_map(static fn (Message $message) => $message->getId(), $this->findEntities($select));
-			}, array_chunk($uids, 1000));
+			}, array_chunk($uids, self::ORACLE_MAX_CHUNK_SIZE));
 		}
 
 		$result = array_map(static fn (Message $message) => $message->getId(), $this->findEntities($select));
@@ -1136,7 +1138,7 @@ public function findIdsGloballyByQuery(IUser $user, SearchQuery $query, ?int $li
 			return array_flat_map(function (array $chunk) use ($select) {
 				$select->setParameter('uids', $chunk, IQueryBuilder::PARAM_INT_ARRAY);
 				return array_map(static fn (Message $message) => $message->getId(), $this->findEntities($select));
-			}, array_chunk($uids, 1000));
+			}, array_chunk($uids, self::ORACLE_MAX_CHUNK_SIZE));
 		}
 
 		return array_map(static fn (Message $message) => $message->getId(), $this->findEntities($select));
@@ -1244,7 +1246,7 @@ public function findByMailboxAndIds(Mailbox $mailbox, string $userId, array $ids
 			->orderBy('sent_at', 'desc');
 
 		$results = [];
-		foreach (array_chunk($ids, 1000) as $chunk) {
+		foreach (array_chunk($ids, self::ORACLE_MAX_CHUNK_SIZE) as $chunk) {
 			$qb->setParameter('ids', $chunk, IQueryBuilder::PARAM_INT_ARRAY);
 			$results[] = $this->findRelatedData($this->findEntities($qb), $userId);
 		}
@@ -1271,7 +1273,7 @@ public function findByIds(string $userId, array $ids, string $sortOrder, string
 			->orderBy($orderBy, $sortOrder);
 
 		$results = [];
-		foreach (array_chunk($ids, 1000) as $chunk) {
+		foreach (array_chunk($ids, self::ORACLE_MAX_CHUNK_SIZE) as $chunk) {
 			$qb->setParameter('ids', $chunk, IQueryBuilder::PARAM_INT_ARRAY);
 			$results[] = $this->findRelatedData($this->findEntities($qb), $userId);
 		}
@@ -1296,7 +1298,7 @@ private function findRecipients(array $messages): array {
 			->where($qb2->expr()->in('message_id', $qb2->createParameter('ids'), IQueryBuilder::PARAM_INT_ARRAY));
 
 		$recipientsResults = [];
-		foreach (array_chunk(array_keys($indexedMessages), 1000) as $chunk) {
+		foreach (array_chunk(array_keys($indexedMessages), self::ORACLE_MAX_CHUNK_SIZE) as $chunk) {
 			$qb2->setParameter('ids', $chunk, IQueryBuilder::PARAM_INT_ARRAY);
 			$result = $qb2->executeQuery();
 			$recipientsResults[] = $result->fetchAll();
@@ -1410,7 +1412,7 @@ public function findNewIds(Mailbox $mailbox, array $ids, ?int $lastMessageTimest
 			->orderBy('m.sent_at', $sortOrder === IMailSearch::ORDER_NEWEST_FIRST ? 'desc' : 'asc');
 
 		$results = [];
-		foreach (array_chunk($ids, 1000) as $chunk) {
+		foreach (array_chunk($ids, self::ORACLE_MAX_CHUNK_SIZE) as $chunk) {
 			$select->setParameter('ids', $chunk, IQueryBuilder::PARAM_INT_ARRAY);
 			$results[] = $this->findIds($select);
 		}
@@ -1472,7 +1474,7 @@ public function deleteOrphans(): void {
 		$query = $qb2
 			->delete($this->getTableName())
 			->where($qb2->expr()->in('id', $qb2->createParameter('ids'), IQueryBuilder::PARAM_INT_ARRAY));
-		foreach (array_chunk($ids, 1000) as $chunk) {
+		foreach (array_chunk($ids, self::ORACLE_MAX_CHUNK_SIZE) as $chunk) {
 			$query->setParameter('ids', $chunk, IQueryBuilder::PARAM_INT_ARRAY);
 			$query->executeStatement();
 		}
@@ -1494,7 +1496,7 @@ public function deleteOrphans(): void {
 		$recipientsQuery = $qb4
 			->delete('mail_recipients')
 			->where($qb4->expr()->in('id', $qb4->createParameter('ids'), IQueryBuilder::PARAM_INT_ARRAY));
-		foreach (array_chunk($ids, 1000) as $chunk) {
+		foreach (array_chunk($ids, self::ORACLE_MAX_CHUNK_SIZE) as $chunk) {
 			$recipientsQuery->setParameter('ids', $chunk, IQueryBuilder::PARAM_INT_ARRAY);
 			$recipientsQuery->executeStatement();
 		}