oracle常用索引创建方式

1.创建缺省索引：
    CREATE INDEX mycolumn_index ON mytable (myclumn) 
    --eg:CREATE INDEX createpsn_index ON ncrcustommade (createpsn)    
    --列名是createpsn
2.删除索引：DROP INDEX mytable.mycolumn_index
3.创建聚集索引：CREATE CLUSTERED INDEX mycolumn_clust_index ON mytable(mycolumn)
4.重复记录建索引：CREATE CLUSTERED INDEX mycolumn_cindex ON mytable(mycolumn) WITH ALLOW_DUP_ROW
5.创建唯一索引：CREATE UNIQUE COUSTERED INDEX myclumn_cindex ON mytable(mycolumn)
6.创建复合索引：CREATE INDEX name_index ON username(firstname,lastname)