| import{_ as t,r as s,o as l,c as r,a as o,d as c,e,b as i,w as n,f as d}from"./app-9073a2e6.js";const u={},v=d(`<h1 id="元数据操作" tabindex="-1"><a class="header-anchor" href="#元数据操作" aria-hidden="true">#</a> 元数据操作</h1><h2 id="数据库管理" tabindex="-1"><a class="header-anchor" href="#数据库管理" aria-hidden="true">#</a> 数据库管理</h2><p>数据库(Database)可以被视为关系数据库中的Database。</p><h3 id="创建数据库" tabindex="-1"><a class="header-anchor" href="#创建数据库" aria-hidden="true">#</a> 创建数据库</h3><p>我们可以根据存储模型建立相应的数据库。如下所示:</p><div class="language-text line-numbers-mode" data-ext="text"><pre class="language-text"><code>IoTDB > CREATE DATABASE root.ln |
| </code></pre><div class="line-numbers" aria-hidden="true"><div class="line-number"></div></div></div><p>需要注意的是,database 的父子节点都不能再设置 database。例如在已经有<code>root.ln</code>和<code>root.sgcc</code>这两个 database 的情况下,创建<code>root.ln.wf01</code> database 是不可行的。系统将给出相应的错误提示,如下所示:</p><div class="language-text line-numbers-mode" data-ext="text"><pre class="language-text"><code>IoTDB> CREATE DATABASE root.ln.wf01 |
| Msg: 300: root.ln has already been created as database. |
| </code></pre><div class="line-numbers" aria-hidden="true"><div class="line-number"></div><div class="line-number"></div></div></div><p>Database 节点名只支持中英文字符、数字、下划线的组合,如果想设置为纯数字或者包含其他字符,需要用反引号(\`\`)把 database 名称引起来。</p><p>还需注意,如果在 Windows 系统上部署,database 名是大小写不敏感的。例如同时创建<code>root.ln</code> 和 <code>root.LN</code> 是不被允许的。</p><h3 id="查看数据库" tabindex="-1"><a class="header-anchor" href="#查看数据库" aria-hidden="true">#</a> 查看数据库</h3>`,11),b=d(`<div class="language-text line-numbers-mode" data-ext="text"><pre class="language-text"><code>IoTDB> show databases |
| IoTDB> show databases root.* |
| IoTDB> show databases root.** |
| </code></pre><div class="line-numbers" aria-hidden="true"><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div></div></div><p>执行结果为:</p><div class="language-text line-numbers-mode" data-ext="text"><pre class="language-text"><code>+-------------+----+-------------------------+-----------------------+-----------------------+ |
| | database| ttl|schema_replication_factor|data_replication_factor|time_partition_interval| |
| +-------------+----+-------------------------+-----------------------+-----------------------+ |
| | root.sgcc|null| 2| 2| 604800| |
| | root.ln|null| 2| 2| 604800| |
| +-------------+----+-------------------------+-----------------------+-----------------------+ |
| Total line number = 2 |
| It costs 0.060s |
| </code></pre><div class="line-numbers" aria-hidden="true"><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div></div></div><h3 id="删除数据库" tabindex="-1"><a class="header-anchor" href="#删除数据库" aria-hidden="true">#</a> 删除数据库</h3><p>用户可以使用<code>DELETE DATABASE <PathPattern></code>语句删除该路径模式匹配的所有的数据库。在删除的过程中,需要注意的是数据库的数据也会被删除。</p><div class="language-text line-numbers-mode" data-ext="text"><pre class="language-text"><code>IoTDB > DELETE DATABASE root.ln |
| IoTDB > DELETE DATABASE root.sgcc |
| // 删除所有数据,时间序列以及数据库 |
| IoTDB > DELETE DATABASE root.** |
| </code></pre><div class="line-numbers" aria-hidden="true"><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div></div></div><h3 id="统计数据库数量" tabindex="-1"><a class="header-anchor" href="#统计数据库数量" aria-hidden="true">#</a> 统计数据库数量</h3><p>用户可以使用<code>COUNT DATABASES <PathPattern></code>语句统计数据库的数量,允许指定<code>PathPattern</code> 用来统计匹配该<code>PathPattern</code> 的数据库的数量</p><p>SQL 语句如下所示:</p><div class="language-text line-numbers-mode" data-ext="text"><pre class="language-text"><code>IoTDB> show databases |
| IoTDB> count databases |
| IoTDB> count databases root.* |
| IoTDB> count databases root.sgcc.* |
| IoTDB> count databases root.sgcc |
| </code></pre><div class="line-numbers" aria-hidden="true"><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div></div></div><p>执行结果为:</p><div class="language-text line-numbers-mode" data-ext="text"><pre class="language-text"><code>+-------------+ |
| | database| |
| +-------------+ |
| | root.sgcc| |
| | root.turbine| |
| | root.ln| |
| +-------------+ |
| Total line number = 3 |
| It costs 0.003s |
| |
| +-------------+ |
| | Database| |
| +-------------+ |
| | 3| |
| +-------------+ |
| Total line number = 1 |
| It costs 0.003s |
| |
| +-------------+ |
| | Database| |
| +-------------+ |
| | 3| |
| +-------------+ |
| Total line number = 1 |
| It costs 0.002s |
| |
| +-------------+ |
| | Database| |
| +-------------+ |
| | 0| |
| +-------------+ |
| Total line number = 1 |
| It costs 0.002s |
| |
| +-------------+ |
| | database| |
| +-------------+ |
| | 1| |
| +-------------+ |
| Total line number = 1 |
| It costs 0.002s |
| </code></pre><div class="line-numbers" aria-hidden="true"><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div></div></div><h3 id="设置异构数据库-进阶操作" tabindex="-1"><a class="header-anchor" href="#设置异构数据库-进阶操作" aria-hidden="true">#</a> 设置异构数据库(进阶操作)</h3><p>在熟悉 IoTDB 元数据建模的前提下,用户可以在 IoTDB 中设置异构的数据库,以便应对不同的生产需求。</p><p>目前支持的数据库异构参数有:</p><table><thead><tr><th>参数名</th><th>参数类型</th><th>参数描述</th></tr></thead><tbody><tr><td>TTL</td><td>Long</td><td>数据库的 TTL</td></tr><tr><td>SCHEMA_REPLICATION_FACTOR</td><td>Integer</td><td>数据库的元数据副本数</td></tr><tr><td>DATA_REPLICATION_FACTOR</td><td>Integer</td><td>数据库的数据副本数</td></tr><tr><td>SCHEMA_REGION_GROUP_NUM</td><td>Integer</td><td>数据库的 SchemaRegionGroup 数量</td></tr><tr><td>DATA_REGION_GROUP_NUM</td><td>Integer</td><td>数据库的 DataRegionGroup 数量</td></tr></tbody></table><p>用户在配置异构参数时需要注意以下三点:</p><ul><li>TTL 和 TIME_PARTITION_INTERVAL 必须为正整数。</li><li>SCHEMA_REPLICATION_FACTOR 和 DATA_REPLICATION_FACTOR 必须小于等于已部署的 DataNode 数量。</li><li>SCHEMA_REGION_GROUP_NUM 和 DATA_REGION_GROUP_NUM 的功能与 iotdb-common.properties 配置文件中的<br><code>schema_region_group_extension_policy</code> 和 <code>data_region_group_extension_policy</code> 参数相关,以 DATA_REGION_GROUP_NUM 为例:<br> 若设置 <code>data_region_group_extension_policy=CUSTOM</code>,则 DATA_REGION_GROUP_NUM 将作为 Database 拥有的 DataRegionGroup 的数量;<br> 若设置 <code>data_region_group_extension_policy=AUTO</code>,则 DATA_REGION_GROUP_NUM 将作为 Database 拥有的 DataRegionGroup 的配额下界,即当该 Database 开始写入数据时,将至少拥有此数量的 DataRegionGroup。</li></ul><p>用户可以在创建 Database 时设置任意异构参数,或在单机/分布式 IoTDB 运行时调整部分异构参数。</p><h4 id="创建-database-时设置异构参数" tabindex="-1"><a class="header-anchor" href="#创建-database-时设置异构参数" aria-hidden="true">#</a> 创建 Database 时设置异构参数</h4><p>用户可以在创建 Database 时设置上述任意异构参数,SQL 语句如下所示:</p><div class="language-text line-numbers-mode" data-ext="text"><pre class="language-text"><code>CREATE DATABASE prefixPath (WITH databaseAttributeClause (COMMA? databaseAttributeClause)*)? |
| </code></pre><div class="line-numbers" aria-hidden="true"><div class="line-number"></div></div></div><p>例如:</p><div class="language-text line-numbers-mode" data-ext="text"><pre class="language-text"><code>CREATE DATABASE root.db WITH SCHEMA_REPLICATION_FACTOR=1, DATA_REPLICATION_FACTOR=3, SCHEMA_REGION_GROUP_NUM=1, DATA_REGION_GROUP_NUM=2; |
| </code></pre><div class="line-numbers" aria-hidden="true"><div class="line-number"></div></div></div><h4 id="运行时调整异构参数" tabindex="-1"><a class="header-anchor" href="#运行时调整异构参数" aria-hidden="true">#</a> 运行时调整异构参数</h4><p>用户可以在 IoTDB 运行时调整部分异构参数,SQL 语句如下所示:</p><div class="language-text line-numbers-mode" data-ext="text"><pre class="language-text"><code>ALTER DATABASE prefixPath WITH databaseAttributeClause (COMMA? databaseAttributeClause)* |
| </code></pre><div class="line-numbers" aria-hidden="true"><div class="line-number"></div></div></div><p>例如:</p><div class="language-text line-numbers-mode" data-ext="text"><pre class="language-text"><code>ALTER DATABASE root.db WITH SCHEMA_REGION_GROUP_NUM=1, DATA_REGION_GROUP_NUM=2; |
| </code></pre><div class="line-numbers" aria-hidden="true"><div class="line-number"></div></div></div><p>注意,运行时只能调整下列异构参数:</p><ul><li>SCHEMA_REGION_GROUP_NUM</li><li>DATA_REGION_GROUP_NUM</li></ul><h4 id="查看异构数据库" tabindex="-1"><a class="header-anchor" href="#查看异构数据库" aria-hidden="true">#</a> 查看异构数据库</h4><p>用户可以查询每个 Database 的具体异构配置,SQL 语句如下所示:</p><div class="language-text line-numbers-mode" data-ext="text"><pre class="language-text"><code>SHOW DATABASES DETAILS prefixPath? |
| </code></pre><div class="line-numbers" aria-hidden="true"><div class="line-number"></div></div></div><p>例如:</p><div class="language-text line-numbers-mode" data-ext="text"><pre class="language-text"><code>IoTDB> SHOW DATABASES DETAILS |
| +--------+--------+-----------------------+---------------------+---------------------+--------------------+-----------------------+-----------------------+------------------+---------------------+---------------------+ |
| |Database| TTL|SchemaReplicationFactor|DataReplicationFactor|TimePartitionInterval|SchemaRegionGroupNum|MinSchemaRegionGroupNum|MaxSchemaRegionGroupNum|DataRegionGroupNum|MinDataRegionGroupNum|MaxDataRegionGroupNum| |
| +--------+--------+-----------------------+---------------------+---------------------+--------------------+-----------------------+-----------------------+------------------+---------------------+---------------------+ |
| |root.db1| null| 1| 3| 604800000| 0| 1| 1| 0| 2| 2| |
| |root.db2|86400000| 1| 1| 604800000| 0| 1| 1| 0| 2| 2| |
| |root.db3| null| 1| 1| 604800000| 0| 1| 1| 0| 2| 2| |
| +--------+--------+-----------------------+---------------------+---------------------+--------------------+-----------------------+-----------------------+------------------+---------------------+---------------------+ |
| Total line number = 3 |
| It costs 0.058s |
| </code></pre><div class="line-numbers" aria-hidden="true"><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div></div></div><p>各列查询结果依次为:</p><ul><li>数据库名称</li><li>数据库的 TTL</li><li>数据库的元数据副本数</li><li>数据库的数据副本数</li><li>数据库的时间分区间隔</li><li>数据库当前拥有的 SchemaRegionGroup 数量</li><li>数据库需要拥有的最小 SchemaRegionGroup 数量</li><li>数据库允许拥有的最大 SchemaRegionGroup 数量</li><li>数据库当前拥有的 DataRegionGroup 数量</li><li>数据库需要拥有的最小 DataRegionGroup 数量</li><li>数据库允许拥有的最大 DataRegionGroup 数量</li></ul>`,38);function m(h,p){const a=s("RouterLink");return l(),r("div",null,[o(` |
| |
| Licensed to the Apache Software Foundation (ASF) under one |
| or more contributor license agreements. See the NOTICE file |
| distributed with this work for additional information |
| regarding copyright ownership. The ASF licenses this file |
| to you under the Apache License, Version 2.0 (the |
| "License"); you may not use this file except in compliance |
| with the License. You may obtain a copy of the License at |
| |
| http://www.apache.org/licenses/LICENSE-2.0 |
| |
| Unless required by applicable law or agreed to in writing, |
| software distributed under the License is distributed on an |
| "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY |
| KIND, either express or implied. See the License for the |
| specific language governing permissions and limitations |
| under the License. |
| |
| `),v,c("p",null,[e("在 database 创建后,我们可以使用 "),i(a,{to:"/zh/UserGuide/Master/stage/Reference/SQL-Reference.html"},{default:n(()=>[e("SHOW DATABASES")]),_:1}),e(" 语句和 "),i(a,{to:"/zh/UserGuide/Master/stage/Reference/SQL-Reference.html"},{default:n(()=>[e("SHOW DATABASES <PathPattern>")]),_:1}),e(" 来查看 database,SQL 语句如下所示:")]),b])}const A=t(u,[["render",m],["__file","Database.html.vue"]]);export{A as default}; |