54 lines
1.6 KiB
Markdown
54 lines
1.6 KiB
Markdown
---
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{
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"title": "TRUNCATE TABLE",
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"language": "zh-CN"
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}
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---
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<!--
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Licensed to the Apache Software Foundation (ASF) under one
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or more contributor license agreements. See the NOTICE file
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distributed with this work for additional information
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regarding copyright ownership. The ASF licenses this file
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to you under the Apache License, Version 2.0 (the
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"License"); you may not use this file except in compliance
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with the License. You may obtain a copy of the License at
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http://www.apache.org/licenses/LICENSE-2.0
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Unless required by applicable law or agreed to in writing,
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software distributed under the License is distributed on an
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"AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
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KIND, either express or implied. See the License for the
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specific language governing permissions and limitations
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under the License.
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-->
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# TRUNCATE TABLE
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## description
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该语句用于清空指定表和分区的数据
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语法：
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TRUNCATE TABLE [db.]tbl[ PARTITION(p1, p2, ...)];
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说明：
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1. 该语句清空数据，但保留表或分区。
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2. 不同于 DELETE，该语句只能整体清空指定的表或分区，不能添加过滤条件。
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3. 不同于 DELETE，使用该方式清空数据不会对查询性能造成影响。
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4. 该操作删除的数据不可恢复。
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5. 使用该命令时，表状态需为 NORMAL，即不允许正在进行 SCHEMA CHANGE 等操作。
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## example
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1. 清空 example_db 下的表 tbl
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TRUNCATE TABLE example_db.tbl;
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2. 清空表 tbl 的 p1 和 p2 分区
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TRUNCATE TABLE tbl PARTITION(p1, p2);
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## keyword
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TRUNCATE,TABLE
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