CREATE TABLE AS SELECT (CTAS)

CREATE TABLE my_table AS SELECT * FROM my_other_table

• The best thing about CTAS is that it does not use rollback segments .
• The above query will copy all the data from the source table to destination table 
• CTAS is a particularly powerful tool for populating or rebuilding a single partition of a partitioned table 

     CREATE TABLE my_table AS SELECT * FROM my_other_table
             where 1= 2

•  The above query will not copy the data from the source table to destination table.It will only create the structure of source table.