>
> I hate to open a potential can of worms here, but here's another
> possibility. I recall someone telling me about a database (InterBase,
> I believe it was) that could have rows with different structures all
> in the same table. In other words, they could add a field to the
> table, and any new rows would have it, while the old ones would not,
> and the database would deal with it on the fly.
> Could we implement some type of "version" field in the table
> structure which would allow this type of thing? If this is
> reasonable, we could have it in 6.4 and potentially never have to
> worry too much about reloading tables after that. With version info
> in each tuple, we could convert the table "as we go" or in some other
> gradual way.
> Of course, the question of how much work it would take to have the
> backend support this needs to be considered, as well as the issue of
> how this would impact performance.
Actually, we already have that. When you add a column to a table, it
does not re-structure the old rows. However, system tables do not
always add columns. Sometimes we change them. Also there is lots
more/different rows for tables, and keeping that straight would be
terrible.
If we can keep the original data files and require initdb and a
re-index, that would be good.
--
Bruce Momjian | 830 Blythe Avenue
maillist@candle.pha.pa.us | Drexel Hill, Pennsylvania 19026
+ If your life is a hard drive, | (610) 353-9879(w)
+ Christ can be your backup. | (610) 853-3000(h)
