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diff --git a/lib/private/DB/QueryBuilder/Partitioned/InvalidPartitionedQueryException.php b/lib/private/DB/QueryBuilder/Partitioned/InvalidPartitionedQueryException.php
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+++ b/lib/private/DB/QueryBuilder/Partitioned/InvalidPartitionedQueryException.php
@@ -0,0 +1,79 @@
+<?php
+
+declare(strict_types=1);
+/**
+ * SPDX-FileCopyrightText: 2024 Nextcloud GmbH and Nextcloud contributors
+ * SPDX-License-Identifier: AGPL-3.0-only
+ */
+
+namespace OC\DB\QueryBuilder\Partitioned;
+
+/**
+ * Partitioned queries impose limitations that queries have to follow:
+ *
+ *  1. Any reference to columns not in the "main table" (the table referenced by "FROM"), needs to explicitly include the
+ *     table or alias the column belongs to.
+ *
+ *     For example:
+ *     ```
+ *       $query->select("mount_point", "mimetype")
+ *         ->from("mounts", "m")
+ *         ->innerJoin("m", "filecache", "f", $query->expr()->eq("root_id", "fileid"));
+ *     ```
+ *     will not work, as the query builder doesn't know that the `mimetype` column belongs to the "filecache partition".
+ *     Instead, you need to do
+ *     ```
+ *     $query->select("mount_point", "f.mimetype")
+ *         ->from("mounts", "m")
+ *         ->innerJoin("m", "filecache", "f", $query->expr()->eq("m.root_id", "f.fileid"));
+ *     ```
+ *
+ *  2. The "ON" condition for the join can only perform a comparison between both sides of the join once.
+ *
+ *     For example:
+ *     ```
+ *      $query->select("mount_point", "mimetype")
+ *         ->from("mounts", "m")
+ *         ->innerJoin("m", "filecache", "f", $query->expr()->andX($query->expr()->eq("m.root_id", "f.fileid"), $query->expr()->eq("m.storage_id", "f.storage")));
+ *     ```
+ *     will not work.
+ *
+ *  3. An "OR" expression in the "WHERE" cannot mention both sides of the join, this does not apply to "AND" expressions.
+ *
+ *      For example:
+ *      ```
+ *       $query->select("mount_point", "mimetype")
+ *          ->from("mounts", "m")
+ *          ->innerJoin("m", "filecache", "f", $query->expr()->eq("m.root_id", "f.fileid")))
+ *          ->where($query->expr()->orX(
+ *              $query->expr()-eq("m.user_id", $query->createNamedParameter("test"))),
+ *              $query->expr()-eq("f.name", $query->createNamedParameter("test"))),
+ *          ));
+ *      ```
+ *      will not work, but.
+ *      ```
+ *       $query->select("mount_point", "mimetype")
+ *          ->from("mounts", "m")
+ *          ->innerJoin("m", "filecache", "f", $query->expr()->eq("m.root_id", "f.fileid")))
+ *          ->where($query->expr()->andX(
+ *              $query->expr()-eq("m.user_id", $query->createNamedParameter("test"))),
+ *              $query->expr()-eq("f.name", $query->createNamedParameter("test"))),
+ *          ));
+ *      ```
+ *      will.
+ *
+ *  4. Queries that join cross-partition cannot use position parameters, only named parameters are allowed
+ *  5. The "ON" condition of a join cannot contain and "OR" expression.
+ *  6. Right-joins are not allowed.
+ *  7. Update, delete and insert statements aren't allowed to contain cross-partition joins.
+ *  8. Queries that "GROUP BY" a column from the joined partition are not allowed.
+ *  9. Any `join` call needs to be made before any `where` call.
+ *  10. Queries that join cross-partition with an "INNER JOIN" or "LEFT JOIN" with a condition on the left side
+ *      cannot use "LIMIT" or "OFFSET" in queries.
+ *
+ * The part of the query running on the sharded table has some additional limitations,
+ * see the `InvalidShardedQueryException` documentation for more information.
+ */
+class InvalidPartitionedQueryException extends \Exception {
+
+}