[GENEAL] dynamically changing table - Mailing list pgsql-general

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Subject [GENEAL] dynamically changing table
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Msg-id dbbf25900903300839g6d4fee5boc1fb0b8244ee869a@mail.gmail.com
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Responses Re: [GENEAL] dynamically changing table  (Emanuel Calvo Franco <postgres.arg@gmail.com>)
Re: [GENEAL] dynamically changing table  (ries van Twisk <pg@rvt.dds.nl>)
Re: [GENEAL] dynamically changing table  (Martijn van Oosterhout <kleptog@svana.org>)
Re: [GENEAL] dynamically changing table  (David Fetter <david@fetter.org>)
FW: [GENEAL] dynamically changing table  (Michael Black <michaelblack75052@hotmail.com>)
Re: [GENEAL] dynamically changing table  (Alban Hertroys <dalroi@solfertje.student.utwente.nl>)
List pgsql-general
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. 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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