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29 lines
1 KiB
PHP
29 lines
1 KiB
PHP
<?php
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declare(strict_types=1);
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/**
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* SPDX-FileCopyrightText: 2024 Nextcloud GmbH and Nextcloud contributors
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* SPDX-License-Identifier: AGPL-3.0-only
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*/
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namespace OC\DB\QueryBuilder\Sharded;
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/**
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* Queries on sharded table has the following limitations:
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*
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* 1. Either the shard key (e.g. "storage") or primary key (e.g. "fileid") must be mentioned in the query.
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* Or the query must be explicitly marked as running across all shards.
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*
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* For queries where it isn't possible to set one of these keys in the query normally, you can set it using `hintShardKey`
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*
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* 2. Insert statements must always explicitly set the shard key
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* 3. A query on a sharded table is not allowed to join on the same table
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* 4. Right joins are not allowed on sharded tables
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* 5. Updating the shard key where the new shard key maps to a different shard is not allowed
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*
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* Moving rows to a different shard needs to be implemented manually. `CrossShardMoveHelper` provides
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* some tools to help make this easier.
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*/
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class InvalidShardedQueryException extends \Exception {
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}
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