On Mon, 27 Feb 2006 07:55:21 -0800, Michelle wrote:

>
> Hi. I am not a DBA and I am dealing with a legacy Sybase database. I
> need to add a column to a couple of tables as well as add additional
> tables to the currently in use production database. I have added the
> necessary columns/tables to a development instance of the database without
> concern for whether anyone was using the database. Now that I am ready to
> make the same changes to production I want to know is it best to have as
> few users as possible on the system or does it really matter?

It depends.

If the columns you add are NULLable (alter table foo add bar sometime
NULL) then this won't have any significant effect on users using the
database as this is a very light operation. On the other hand, if you are
adding columns that are NOT NULL then there will be a period of time when
the table will be locked. The length of the period will depend on the size
of the table and the speed of your system.

Adding the tables to the database shouldn't have any effect on the users
currently using the database.

Michael
--
Michael Peppler [TeamSybase] mpeppler@peppler.org - http://www.peppler.org/
Sybase DBA/Developer
Sybase on Linux FAQ: http://www.peppler.org/FAQ/linux.html