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

In article <37504d67_at_discussions>,
  "sganesh" <sganesh_at_apple.com> wrote:
>
> 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..

This is wrong. "WHERE 1 = 2" will NOT transfer the data over. Therefore, your table will be created very quickly.

>
> 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
> >
> >
> >
>
>

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Share what you know. Learn what you don't. Received on Tue Jun 01 1999 - 14:49:06 CDT