Re: [GENEAL] dynamically changing table

On Mon, Mar 30, 2009 at 05:39:19PM +0200, A B wrote:
> Hi,
> In the next project I'm going to have a number of colums in my tables,
> but I don't know how many, they change.

Stop right there. You need to get some sanity into your project,
either by changing that requirement, or by not using an RDBMS for it.

Cheers,
David.
> They all use integers as
> datatype though.. One day, I get 2 new columns, a week later I loose
> one column, and so on in a random pattern.
>
> I will most likely have a few million rows of data so I just wonder if
> there are any problems with running
> alter table x add column .....
> or
> alter table x drop column .....
>
> Adding a column, will it place data "far away" on the disc so that
> select * from x where id=y will result in not quite optimal
> performance since it has to fetch columns from a lot of different
> places?
> Will deleting a column result in a lot of empty space that will anoy
> me later on?
>
> Are there any other clever solutions of this problem?
>
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