Re: "rename" and "create table x as select *" questions

Hi ,

1. Rename will not take time however large the table is, it will just update some dict tables.
2. This create statement WILL TRANSFER ALL DATA FROM SECOND TABLE MEETING THE CONDITION TO FIRST TABLE. So it will take very long time..

Sanjay.

Ying-fen Hu <yhu_at_generalmicro.com> wrote:
>Dear Oracle Gurus,>
>I have two questions:
>
>1. Will "rename" take a long time if the table is large? What are
>involved in the rename process?
>2. Will "create table x as select * from table y where 1=2;" take a
>long time if table y is very large (8 million rows)? I think it will.
>Although, this statement will create the structure only and no data are
>transferred to table y, the "where" clause will go through the usual SQL
>process. Therefore, if the table is large (millions of rows), the
>statement will take longer than if the table is smaller (hundreds of
>rows). Is it correct? I'd like to know what's happening behind the
>statement.
>
>Thank you in advance for your reply. For reply, please also e-mail to
>huy_at_ncr.disa.mil.
>
>Ying-fen Hu
>
>
>
Received on Sat May 29 1999 - 16:26:15 CDT