SqlServer2008根据现有表，获取该表的分区创建脚本-Mysql Tutorial-php.cn

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SqlServer2008根据现有表，获取该表的分区创建脚本

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Jun 07, 2016 pm 03:45 PM

PartitionObtain

1 *============================================================== 2 名称: [ GetMSSQLTableScript ] 3 功能: 获取customize单个表的mysql脚本 4 创建：2015年3月23日 5 参数： @DBName -- 数据库名称 6 @TBName -- 表名 7 @SchemeName -- 数据库表引用的

<span>  1</span> <span>*==============================================================</span>
<span>  2</span> 名称: <span>[</span><span>GetMSSQLTableScript</span><span>]</span>
<span>  3</span> <span>功能: 获取customize单个表的mysql脚本 
</span><span>  4</span> <span>创建：2015年3月23日
</span><span>  5</span> 参数：<span>@DBName</span>            <span>--</span><span>数据库名称</span>
<span>  6</span>       <span>@TBName</span>            <span>--</span><span>表名</span>
<span>  7</span>       <span>@SchemeName</span>        <span>--</span><span>数据库表引用的Scheme</span>
<span>  8</span>       <span>@PartitionScheme</span>    <span>--</span><span>分区Scheme</span>
<span>  9</span>       <span>@PartitionField</span>    <span>--</span><span>该表使用的分区字段      </span>
<span> 10</span>       <span>@SQL</span>                <span>--</span><span>输出脚本</span>
<span> 11</span> <span>==============================================================*/</span>
<span> 12</span> <span>ALTER</span> <span>PROCEDURE</span> <span>[</span><span>Tuning</span><span>]</span>.<span>[</span><span>GetMSSQLTableScript</span><span>]</span><span> (
</span><span> 13</span>     <span>@DBName</span> <span>nvarchar</span>(<span>64</span><span>),
</span><span> 14</span>     <span>@SchemeName</span> <span>nvarchar</span>(<span>32</span><span>),
</span><span> 15</span>     <span>@TBName</span> <span>nvarchar</span>(<span>128</span><span>),    
</span><span> 16</span>     <span>@PartitionScheme</span> <span>nvarchar</span>(<span>32</span><span>),
</span><span> 17</span>     <span>@PartitionField</span> <span>nvarchar</span>(<span>32</span><span>),    
</span><span> 18</span>     <span>@SQL</span> <span>nvarchar</span>(<span>max</span><span>) OUTPUT
</span><span> 19</span> <span>)
</span><span> 20</span> <span>AS</span>  
<span> 21</span> <span>Begin</span>
<span> 22</span>     <span>declare</span> <span>@table_script</span> <span>nvarchar</span>(<span>max</span>) <span>--</span><span>建表的脚本</span>
<span> 23</span>     <span>declare</span> <span>@index_script</span> <span>nvarchar</span>(<span>max</span>) <span>--</span><span>索引的脚本</span>
<span> 24</span>     <span>declare</span> <span>@default_script</span> <span>nvarchar</span>(<span>max</span>) <span>--</span><span>默认值的脚本</span>
<span> 25</span>     <span>declare</span> <span>@check_script</span> <span>nvarchar</span>(<span>max</span>) <span>--</span><span>check约束的脚本</span>
<span> 26</span>     <span>declare</span> <span>@sql_cmd</span> <span>nvarchar</span>(<span>max</span>)  <span>--</span><span>动态SQL命令</span>
<span> 27</span>     <span>declare</span> <span>@err_info</span> <span>varchar</span>(<span>200</span><span>)
</span><span> 28</span>     <span>set</span> <span>@TBName</span> <span>=</span> <span>UPPER</span>(<span>@TBName</span><span>);
</span><span> 29</span>     <span>if</span> <span>OBJECT_ID</span>(<span>@DBName</span><span>+</span><span>'</span><span>.</span><span>'</span><span>+</span><span>@SchemeName</span><span>+</span><span>'</span><span>.</span><span>'</span><span>+</span><span>@TBName</span>) <span>is</span> <span>null</span>
<span> 30</span>     <span>BEGIN</span>
<span> 31</span>         <span>set</span> <span>@err_info</span><span>=</span><span>'</span><span>对象:</span><span>'</span><span>+</span><span>@DBName</span><span>+</span><span>'</span><span>.</span><span>'</span><span>+</span><span>@SchemeName</span><span>+</span><span>'</span><span>.</span><span>'</span><span>+</span><span>@TBName</span><span>+</span><span>'</span><span>不存在!</span><span>'</span>
<span> 32</span>         <span>raiserror</span>(<span>@err_info</span>,<span>16</span>,<span>1</span><span>)
</span><span> 33</span>         <span>return</span>
<span> 34</span>     <span>END</span>
<span> 35</span> 
<span> 36</span>     <span>--</span><span>--------------------生成创建表脚本----------------------------</span>
<span> 37</span>     <span>--</span><span>1.添加算定义字段</span>
<span> 38</span>     <span>set</span> <span>@table_script</span> <span>=</span> <span>'</span><span>CREATE TABLE </span><span>'</span><span>+</span><span>@SchemeName</span><span>+</span><span>'</span><span>.</span><span>'</span><span>+</span><span>@TBName</span><span>+</span><span>'</span>
<span> 39</span> <span>    (</span><span>'</span><span>+</span><span>char</span>(<span>13</span>)<span>+</span><span>char</span>(<span>10</span><span>);
</span><span> 40</span>      
<span> 41</span>      
<span> 42</span>     <span>--</span><span>添加表中的其它字段</span>
<span> 43</span>     <span>set</span> <span>@sql_cmd</span><span>=</span>N<span>'</span>
<span> 44</span> <span>    use </span><span>'</span><span>+</span><span>@DBName</span><span>+</span><span>'</span>
<span> 45</span> <span>    set @table_script=</span><span>''''</span> 
<span> 46</span> <span>    select @table_script=@table_script+
</span><span> 47</span>             <span>''</span><span> [</span><span>''</span><span>+t.NAME+</span><span>''</span><span>] </span><span>''</span>
<span> 48</span> <span>            +(case when t.xusertype in (175,62,239,59,122,165,173) then </span><span>''</span><span>[</span><span>''</span><span>+p.name+</span><span>''</span><span>] (</span><span>''</span><span>+convert(varchar(30),isnull(t.prec,</span><span>''''</span><span>))+</span><span>''</span><span>)</span><span>''</span>
<span> 49</span> <span>                  when t.xusertype in (231) and t.length=-1 then </span><span>''</span><span>[ntext]</span><span>''</span>
<span> 50</span> <span>                  when t.xusertype in (231) and t.length-1 then </span><span>''</span><span>[</span><span>''</span><span>+p.name+</span><span>''</span><span>] (</span><span>''</span><span>+convert(varchar(30),isnull(t.prec,</span><span>''''</span><span>))+</span><span>''</span><span>)</span><span>''</span>
<span> 51</span> <span>                 when t.xusertype in (167) and t.length=-1 then </span><span>''</span><span>[text]</span><span>''</span>
<span> 52</span> <span>                  when t.xusertype in (167) and t.length-1 then </span><span>''</span><span>[</span><span>''</span><span>+p.name+</span><span>''</span><span>] (</span><span>''</span><span>+convert(varchar(30),isnull(t.prec,</span><span>''''</span><span>))+</span><span>''</span><span>)</span><span>''</span>
<span> 53</span> <span>                  when t.xusertype in (106,108) then </span><span>''</span><span>[</span><span>''</span><span>+p.name+</span><span>''</span><span>] (</span><span>''</span><span>+convert(varchar(30),isnull(t.prec,</span><span>''''</span><span>))+</span><span>''</span><span>,</span><span>''</span><span>+convert(varchar(30),isnull(t.scale,</span><span>''''</span><span>))+</span><span>''</span><span>)</span><span>''</span>
<span> 54</span> <span>                  else </span><span>''</span><span>[</span><span>''</span><span>+p.name+</span><span>''</span><span>]</span><span>''</span>
<span> 55</span> <span>             END)
</span><span> 56</span> <span>             +(case when t.isnullable=1 then </span><span>''</span><span> null</span><span>''</span><span> else </span><span>''</span><span> not null </span><span>''</span><span>end)
</span><span> 57</span> <span>             +(case when COLUMNPROPERTY(t.ID, t.NAME, </span><span>''</span><span>ISIDENTITY</span><span>''</span><span>)=1 then </span><span>''</span><span> identity</span><span>''</span><span> else </span><span>''''</span><span> end)
</span><span> 58</span> <span>             +</span><span>''</span><span>,</span><span>''</span><span>+char(13)+char(10)
</span><span> 59</span> <span>    from syscolumns t join systypes p  on t.xusertype = p.xusertype
</span><span> 60</span> <span>    where t.ID=OBJECT_ID(</span><span>'''</span><span>+</span><span>@SchemeName</span><span>+</span><span>'</span><span>.</span><span>'</span><span>+</span><span>@TBName</span><span>+</span><span>'''</span><span>)
</span><span> 61</span> <span>    ORDER BY  t.COLID; 
</span><span> 62</span>     <span>'</span>
<span> 63</span>     <span>EXEc</span> sp_executesql <span>@sql_cmd</span>,N<span>'</span><span>@table_script varchar(max) output</span><span>'</span>,<span>@sql_cmd</span><span> output
</span><span> 64</span>     <span>set</span> <span>@table_script</span><span>=</span><span>@table_script</span><span>+</span><span>@sql_cmd</span>
<span> 65</span>     <span>IF</span> <span>len</span>(<span>@table_script</span>)<span>></span><span>0</span>
<span> 66</span>         <span>set</span> <span>@table_script</span><span>=</span><span>substring</span>(<span>@table_script</span>,<span>1</span>,<span>len</span>(<span>@table_script</span>)<span>-</span><span>3</span>)<span>+</span><span>char</span>(<span>13</span>)<span>+</span><span>char</span>(<span>10</span><span>)
</span><span> 67</span>             <span>+</span><span>'</span><span>)On </span><span>'</span><span>+</span><span>@PartitionScheme</span><span>+</span><span>'</span><span>(</span><span>'</span><span>+</span><span>@PartitionField</span><span>+</span><span>'</span><span>)
</span><span> 68</span>             <span>'</span><span>+</span><span>char</span>(<span>13</span>)<span>+</span><span>char</span>(<span>10</span><span>)
</span><span> 69</span>             <span>--</span><span>+'GO'</span>
<span> 70</span>             <span>+</span><span>char</span>(<span>13</span>)<span>+</span><span>char</span>(<span>10</span>)<span>+</span><span>char</span>(<span>13</span>)<span>+</span><span>char</span>(<span>10</span><span>)
</span><span> 71</span>         
<span> 72</span>     <span>--</span><span>------------------生成索引脚本---------------------------------------</span>
<span> 73</span>     <span>set</span> <span>@index_script</span><span>=</span><span>''</span>
<span> 74</span>     <span>set</span> <span>@sql_cmd</span><span>=</span>N<span>'</span>
<span> 75</span> <span>    use </span><span>'</span><span>+</span><span>@DBName</span><span>+</span><span>'</span>
<span> 76</span> <span>    declare @ct int
</span><span> 77</span> <span>    declare @scheme nvarchar(32)
</span><span> 78</span> <span>    declare @indid int      --当前索引ID
</span><span> 79</span> <span>    declare @p_indid int    --前一个索引ID
</span><span> 80</span> <span>    declare @partitionField nvarchar(32)
</span><span> 81</span> <span>    set @partitionField=</span><span>'''</span><span>+</span><span>@PartitionField</span><span>+</span><span>'''</span>
<span> 82</span> <span>    select @indid=-1, @p_indid=0,@ct=0    --初始化，以后用@indid和@p_indid判断是否索引ID发生变化
</span><span> 83</span> <span>    set @index_script=</span><span>''''</span>
<span> 84</span> <span>    set @scheme=</span><span>'''</span><span>+</span><span>@SchemeName</span><span>+</span><span>'''</span>
<span> 85</span> <span>    select @indid=INDID
</span><span> 86</span> <span>        ,@index_script=@index_script
</span><span> 87</span> <span>        +(case when @indid@p_indid and @ct>0 
</span><span> 88</span> <span>            then </span><span>''</span><span>)</span><span>''</span><span>+char(13)+char(10)    +char(13)+char(10)
</span><span> 89</span> <span>            else </span><span>''''</span> 
<span> 90</span> <span>        end)
</span><span> 91</span> <span>        +(case when @indid@p_indid and UNIQ=</span><span>''</span><span>PRIMARY KEY</span><span>''</span> 
<span> 92</span> <span>              then </span><span>''</span><span>ALTER TABLE </span><span>''</span><span>+TABNAME+</span><span>''</span><span> ADD CONSTRAINT </span><span>''</span><span>+name+</span><span>''</span><span> PRIMARY KEY </span><span>''</span><span>+cluster+char(13)+char(10)+</span><span>''</span><span>(</span><span>''</span><span>+char(13)+char(10)+</span><span>''</span>    <span>''</span><span>+COLNAME+</span><span>''</span><span>,</span><span>''</span><span>+@partitionField+char(13)+char(10)
</span><span> 93</span> <span>              when @indid@p_indid and UNIQ=</span><span>''</span><span>UNIQUE</span><span>''</span> 
<span> 94</span> <span>              then </span><span>''</span><span>ALTER TABLE </span><span>''</span><span>+TABNAME+</span><span>''</span><span> ADD CONSTRAINT </span><span>''</span><span>+name+</span><span>''</span><span> UNIQUE </span><span>''</span><span>+cluster+char(13)+char(10)+</span><span>''</span><span>(</span><span>''</span><span>+char(13)+char(10)+</span><span>''</span>    <span>''</span><span>+COLNAME+</span><span>''</span><span>,</span><span>''</span><span>+@partitionField+char(13)+char(10)
</span><span> 95</span> <span>              when @indid@p_indid and UNIQ=</span><span>''</span><span>INDEX</span><span>''</span>     
<span> 96</span> <span>              then </span><span>''</span><span>CREATE </span><span>''</span><span>+cluster+</span><span>''</span><span> INDEX </span><span>''</span><span>+name+</span><span>''</span><span> ON </span><span>''</span><span>+TABNAME+char(13)+char(10)+</span><span>''</span><span>(</span><span>''</span><span>+char(13)+char(10)+</span><span>''</span>    <span>''</span><span>+COLNAME+char(13)+char(10)
</span><span> 97</span> <span>              when @indid=@p_indid
</span><span> 98</span> <span>              then  </span><span>''</span><span>    ,</span><span>''</span><span>+COLNAME+char(13)+char(10)
</span><span> 99</span> <span>         end)
</span><span>100</span> <span>        ,@ct=@ct+1
</span><span>101</span> <span>        ,@p_indid=@indid
</span><span>102</span> <span>    from 
</span><span>103</span> <span>    (
</span><span>104</span> <span>        SELECT A.INDID,B.KEYNO
</span><span>105</span> <span>            ,NAME,@scheme+</span><span>''</span><span>.</span><span>''</span><span>+(SELECT NAME FROM SYSOBJECTS WHERE ID=A.ID) AS TABNAME,
</span><span>106</span> <span>            (SELECT NAME FROM SYSCOLUMNS WHERE ID=B.ID AND COLID=B.COLID) AS COLNAME,
</span><span>107</span> <span>            (CASE WHEN EXISTS(SELECT 1 FROM SYSOBJECTS WHERE NAME=A.NAME AND XTYPE=</span><span>''</span><span>UQ</span><span>''</span><span>) THEN </span><span>''</span><span>UNIQUE</span><span>''</span> 
<span>108</span> <span>                  WHEN EXISTS(SELECT 1 FROM SYSOBJECTS WHERE NAME=A.NAME AND XTYPE=</span><span>''</span><span>PK</span><span>''</span><span>) THEN </span><span>''</span><span>PRIMARY KEY</span><span>''</span>
<span>109</span> <span>                  ELSE </span><span>''</span><span>INDEX</span><span>''</span><span> END)  AS UNIQ,
</span><span>110</span> <span>            (CASE WHEN A.INDID=1 THEN </span><span>''</span><span>CLUSTERED</span><span>''</span><span> WHEN A.INDID>1 THEN </span><span>''</span><span>NONCLUSTERED</span><span>''</span><span> END) AS CLUSTER
</span><span>111</span> <span>        FROM SYSINDEXES A INNER JOIN SYSINDEXKEYS B ON A.INDID=B.INDID AND A.ID=B.ID
</span><span>112</span> <span>        WHERE A.ID=OBJECT_ID(</span><span>'''</span><span>+</span><span>@SchemeName</span><span>+</span><span>'</span><span>.</span><span>'</span><span>+</span><span>@TBName</span><span>+</span><span>'''</span><span>) and a.indid0 /*如果该表是一个分区表，就必须添加条件：and b.keyno0*/
</span><span>113</span> <span>    ) t
</span><span>114</span> <span>    ORDER BY INDID,KEYNO</span><span>'</span>
<span>115</span>     <span>EXEc</span> sp_executesql <span>@sql_cmd</span>,N<span>'</span><span>@index_script varchar(max) output</span><span>'</span>,<span>@sql_cmd</span><span> output
</span><span>116</span>     <span>set</span> <span>@index_script</span><span>=</span><span>@sql_cmd</span>
<span>117</span>     <span>IF</span> <span>len</span>(<span>@index_script</span>)<span>></span><span>0</span>
<span>118</span>         <span>set</span> <span>@index_script</span><span>=</span><span>@index_script</span><span>+</span><span>'</span><span>)</span><span>'</span><span>+</span><span>char</span>(<span>13</span>)<span>+</span><span>char</span>(<span>10</span><span>)
</span><span>119</span>         <span>--</span><span>+'go'</span>
<span>120</span>         <span>+</span><span>char</span>(<span>13</span>)<span>+</span><span>char</span>(<span>10</span>)<span>+</span><span>char</span>(<span>13</span>)<span>+</span><span>char</span>(<span>10</span><span>)
</span><span>121</span>     <span>--</span><span>生成默认值约束</span>
<span>122</span>     <span>set</span> <span>@sql_cmd</span><span>=</span><span>'</span>
<span>123</span> <span>    use </span><span>'</span><span>+</span><span>@DBName</span><span>+</span><span>'</span>
<span>124</span> <span>    declare @scheme nvarchar(32)
</span><span>125</span> <span>    declare @partitionField nvarchar(32)
</span><span>126</span> <span>    set @partitionField=</span><span>'''</span><span>+</span><span>@PartitionField</span><span>+</span><span>'''</span>
<span>127</span> <span>    set @scheme=</span><span>'''</span><span>+</span><span>@SchemeName</span><span>+</span><span>'''</span>
<span>128</span> <span>    set @default_script=</span><span>''''</span>
<span>129</span> <span>    SELECT @default_script=@default_script
</span><span>130</span> <span>            +</span><span>''</span><span>ALTER TABLE </span><span>''</span><span>+@scheme+</span><span>''</span><span>.</span><span>''</span><span>+OBJECT_NAME(O.PARENT_OBJ)
</span><span>131</span> <span>            +</span><span>''</span><span> ADD CONSTRAINT </span><span>''</span><span>+O.NAME+</span><span>''</span><span> default </span><span>''</span><span>+t.text+</span><span>''</span><span> for </span><span>''</span><span>+C.NAME+char(13)+char(10)+char(13)+char(10)
</span><span>132</span> <span>    FROM SYSOBJECTS O INNER JOIN SYSCOMMENTS T ON O.ID=T.ID
</span><span>133</span> <span>        INNER JOIN SYSCOLUMNS C ON O.PARENT_OBJ=C.ID AND C.CDEFAULT=T.ID
</span><span>134</span> <span>    WHERE O.XTYPE=</span><span>''</span><span>D</span><span>''</span><span> AND O.PARENT_OBJ=OBJECT_ID(</span><span>'''</span><span>+</span><span>@SchemeName</span><span>+</span><span>'</span><span>.</span><span>'</span><span>+</span><span>@TBName</span><span>+</span><span>'''</span><span>)</span><span>'</span>
<span>135</span>     <span>EXEc</span> sp_executesql <span>@sql_cmd</span>,N<span>'</span><span>@default_script varchar(max) output</span><span>'</span>,<span>@sql_cmd</span><span> output
</span><span>136</span>     <span>set</span> <span>@default_script</span><span>=</span><span>@sql_cmd</span><span>+</span><span>char</span>(<span>13</span>)<span>+</span><span>char</span>(<span>10</span><span>)
</span><span>137</span> 
<span>138</span>     <span>set</span> <span>@SQL</span><span>=</span><span>@table_script</span><span>+</span><span>@index_script</span><span>+</span><span>@default_script</span>
<span>139</span>     <span>declare</span> <span>@len</span> <span>int</span>,<span>@n</span> <span>int</span>
<span>140</span>     <span>set</span> <span>@len</span><span>=</span><span>LEN</span>(<span>@SQL</span><span>)
</span><span>141</span>     <span>set</span> <span>@n</span><span>=</span><span>0</span>
<span>142</span>     <span>while</span>(<span>@len</span><span>></span><span>0</span><span>)
</span><span>143</span>     <span>BEGIN</span>
<span>144</span>       <span>PRINT</span>(<span>substring</span>(<span>@SQL</span>,<span>@n</span><span>*</span><span>4000</span><span>+</span><span>1</span>,<span>4000</span><span>));
</span><span>145</span>       <span>set</span> <span>@n</span><span>=</span><span>@n</span><span>+</span><span>1</span>
<span>146</span>       <span>set</span> <span>@len</span><span>=</span><span>@len</span><span>-</span><span>4000</span><span>;
</span><span>147</span>     <span>END</span>
<span>148</span> <span>End</span>

该函数的原创作者：http://www.cnblogs.com/champaign/p/3492510.html

本人及修改了一部分内容，让该存储过程更灵活点。

公司DBA支持给建议不要用sysindexkeys来查找对应的列，而是使用syscolumns来提到：

比如：select * from syscolumns where id=object_id('dx.Article');

select * from sys.index_columns where object_id=object_id('dx.Article');

Statement

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Explain the ACID properties (Atomicity, Consistency, Isolation, Durability).Apr 16, 2025 am 12:20 AM

ACID attributes include atomicity, consistency, isolation and durability, and are the cornerstone of database design. 1. Atomicity ensures that the transaction is either completely successful or completely failed. 2. Consistency ensures that the database remains consistent before and after a transaction. 3. Isolation ensures that transactions do not interfere with each other. 4. Persistence ensures that data is permanently saved after transaction submission.

MySQL: Database Management System vs. Programming LanguageApr 16, 2025 am 12:19 AM

MySQL is not only a database management system (DBMS) but also closely related to programming languages. 1) As a DBMS, MySQL is used to store, organize and retrieve data, and optimizing indexes can improve query performance. 2) Combining SQL with programming languages, embedded in Python, using ORM tools such as SQLAlchemy can simplify operations. 3) Performance optimization includes indexing, querying, caching, library and table division and transaction management.

MySQL: Managing Data with SQL CommandsApr 16, 2025 am 12:19 AM

MySQL uses SQL commands to manage data. 1. Basic commands include SELECT, INSERT, UPDATE and DELETE. 2. Advanced usage involves JOIN, subquery and aggregate functions. 3. Common errors include syntax, logic and performance issues. 4. Optimization tips include using indexes, avoiding SELECT* and using LIMIT.

MySQL's Purpose: Storing and Managing Data EffectivelyApr 16, 2025 am 12:16 AM

MySQL is an efficient relational database management system suitable for storing and managing data. Its advantages include high-performance queries, flexible transaction processing and rich data types. In practical applications, MySQL is often used in e-commerce platforms, social networks and content management systems, but attention should be paid to performance optimization, data security and scalability.

SQL and MySQL: Understanding the RelationshipApr 16, 2025 am 12:14 AM

The relationship between SQL and MySQL is the relationship between standard languages and specific implementations. 1.SQL is a standard language used to manage and operate relational databases, allowing data addition, deletion, modification and query. 2.MySQL is a specific database management system that uses SQL as its operating language and provides efficient data storage and management.

Explain the role of InnoDB redo logs and undo logs.Apr 15, 2025 am 12:16 AM

InnoDB uses redologs and undologs to ensure data consistency and reliability. 1.redologs record data page modification to ensure crash recovery and transaction persistence. 2.undologs records the original data value and supports transaction rollback and MVCC.

What are the key metrics to look for in an EXPLAIN output (type, key, rows, Extra)?Apr 15, 2025 am 12:15 AM

Key metrics for EXPLAIN commands include type, key, rows, and Extra. 1) The type reflects the access type of the query. The higher the value, the higher the efficiency, such as const is better than ALL. 2) The key displays the index used, and NULL indicates no index. 3) rows estimates the number of scanned rows, affecting query performance. 4) Extra provides additional information, such as Usingfilesort prompts that it needs to be optimized.

What is the Using temporary status in EXPLAIN and how to avoid it?Apr 15, 2025 am 12:14 AM

Usingtemporary indicates that the need to create temporary tables in MySQL queries, which are commonly found in ORDERBY using DISTINCT, GROUPBY, or non-indexed columns. You can avoid the occurrence of indexes and rewrite queries and improve query performance. Specifically, when Usingtemporary appears in EXPLAIN output, it means that MySQL needs to create temporary tables to handle queries. This usually occurs when: 1) deduplication or grouping when using DISTINCT or GROUPBY; 2) sort when ORDERBY contains non-index columns; 3) use complex subquery or join operations. Optimization methods include: 1) ORDERBY and GROUPB

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