[转]Oracle常用命令[2]

sql> truncate table table_name;

10.drop a table
sql> drop table table_name [cascade constraints];

11.drop a column
sql> alter table table_name drop column comments cascade constraints checkpoint 1000;
alter table table_name drop columns continue;

12.mark a column as unused
sql> alter table table_name set unused column comments cascade constraints;
alter table table_name drop unused columns checkpoint 1000;
alter table orders drop columns continue checkpoint 1000