1.不能为用户自定义的类型的属性建立索引
文档这样说：You cannot create an index on columns or attributes whose type is user-defined
column
Specify the name of a column in the table. A bitmap index can have a maximum of 30 columns. Other indexes can have as many as 32 columns. Restriction: You cannot create an index on columns or attributes whose type is user-defined, LONG, LONG RAW, LOB, or REF, except that Oracle supports an index on REF type columns or attributes that have been defined with a SCOPE clause.2.select table_name from user_tables where table_name='YOURTABLE';
文档这样说：You cannot create an index on columns or attributes whose type is user-defined
column
Specify the name of a column in the table. A bitmap index can have a maximum of 30 columns. Other indexes can have as many as 32 columns. Restriction: You cannot create an index on columns or attributes whose type is user-defined, LONG, LONG RAW, LOB, or REF, except that Oracle supports an index on REF type columns or attributes that have been defined with a SCOPE clause.2.select table_name from user_tables where table_name='YOURTABLE';
关于第二个问题
应该有判断语句阿，判断目前的方案中是否有表名与将要建立的新表表名重合，如果有，才drop掉的阿，土土的问，脚本如何写捏？