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Index-Organized TablesIOT表要求必须有主键.heap表可以没有主键.没有主键的表,不能称之为IOT表.IOT and Heap TablesCompared to heap tables,IOTs have:Faster key-based access to table dataReduced storage requirementsSecondary indexes and logical rowidsIOTs have the following restrictions:-Must have a primary key-Cannot be clusteredCr 阅读全文
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connection as sysdbaSQL> grant select any dictionary to user_name; 阅读全文
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Compressed IndexesCREATE INDEX t_idx on t(owner,object_type,object_name);SQL> ANALYZE INDEX t_idx validate structure;Index analyzed.SQL> create table idx_stats 2 as 3 select 'noncompressed' what,a.* from index_stats a;Table created.lab1->dataSQL> drop index t_idx;Index dropped.SQ 阅读全文
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ObjectivesAfter completing this lesson,you should be able to do the following:Explain the role of the DBA in tuning applications.Move tables using the ALTER TABLE command.Redefine a table onlineCreate different types of indexesBuild and manage index-organized tablesExplain and plan OLTP,DSS,and hybr 阅读全文