Oracle_SQL学习笔记
[font=宋体][size=10.5pt]1[/size][/font][font=宋体][size=10.5pt]．SQL并行查询[/size][/font][font=Times New Roman]alter session enable parallel dml[/font][font=Times New Roman]execute immediate 'alter session enable parallel dml'; --[/font][font=宋体]修改会话并行[/font][font=Times New Roman]DML
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[font=Times New Roman]select /*+parallel(a,4)*/ * from table_name a
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[font=Times New Roman]select /*+parallel(a,8)*/ * from table_name a
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[font=Times New Roman]select /*+parallel(a,4) parallel(b,4) parallel(c,4)*/ a.*,b.*,c.* [/font]
[font=Times New Roman]from table_name1 a,table_name2 b,table_name c
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[font=Times New Roman]insert /*+parallel(t,4)*/ into table_name t
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[font=Times New Roman]insert /*+parallel(t,8)*/ into table_name t
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[font=Times New Roman]/*+parallel(t,8)*/ [/font][font=宋体]并行处理，一般为[/font][font=Times New Roman]CPU[/font][font=宋体]的倍数如：[/font][font=Times New Roman]4[/font][font=宋体]，[/font][font=Times New Roman]8[/font][font=宋体]等[/font][font=Times New Roman],[/font][font=宋体]在执行类型[/font][font=Times New Roman]SQL[/font][font=宋体]必须先运行[/font][font=Times New Roman]:alter session enable parallel dml
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