Re: Oracle DDL

And in simple terms DDL, Data Definition Language, means anything that affects the structure of the Oracle Database -- creating, altering, dropping tables, indices, tablespaces, defining a new database itself is DDL.

DML is modifying the CONTENTS of such objects; so adding a new order for a customer, or adding a customer, would be a DML, or modification operation. DDL, would mean creating a new table to hold some brand new sort of information, or adding columns to existing tables, and otherwise changing the fundamental structure of your database.

Beware, any DDL operation as benign sounding as "TRUNCATE TABLE xxxx" (which beats the heck out of DELETE from FOO_FOO; in system overhead.).. All DDL commands have an implicit "automatic commit:, meaning if the last thing you did before adding a column, creating a table or whatever, was DELETE FROM CUSTOMER_MASTER; (never forget your WHERE clauses!!), when you issue a DDL command subsequent to that, well, hope you didn't make any booboos that ROLLBACK would have saved you from... because it's too late.

Or, to say it more broadly, be VERY careful before you hit that ENTER key.

Bonne chance!

RSH.
"Laurent Boutet" <laurent.boutet1_at_libertysurf.fr> wrote in message news:a5i5pb$41p$1_at_reader1.imaginet.fr...
> Hi,
>
> Is there anybody who could tell me more about SQL Oracle DDL, where could
I
> find documentation, what is exactly SQL Oracle DDL ...
>
> Thanks in advance,
> Laurent
>
>
Received on Tue Mar 05 2002 - 07:44:43 CET