BETWEEN Node & DROP COLUMN

Hi All,

I have given up working on the BETWEEN node. It got to the stage where I
realised I was really out of my depth! Rod Taylor has indicated an interest
in the problem and I have sent him my latest patch, so hopefully he'll be
able to crack it.

So instead, I've taken up with the DROP COLUMN crusade. It seems that the
following are the jobs that need to be done:

* Add attisdropped to pg_attribute
- Looking for takers for this one, otherwise I'll look into it.
* Fill out AlterTableDropColumn
- I've done this, with the assumption that attisdropped exists. It sets
attisdropped to true, drops the column default and renames the column.
(Plus does all other normal ALTER TABLE checks)
* Modify parser and other places to ignore dropped columns
- This is also up for grabs.
* Modify psql and pg_dump to handle dropped columns
- I've done this.

Once the above is done, we have a working drop column implementation.

* Modify all other interfaces, JDBC, etc. to handle dropped cols.
- I think this can be suggested to the relevant developers once the above
is committed!

* Modify VACUUM to add a RECLAIM option to reduce on disk table size.
- This is out of my league, so it's up for grabs

I have approached a couple of people off-list to see if they're interested
in helping, so please post to the list if you intend to work on something.

It has also occurred to me that once drop column exists, users will be able
to change the type of their columns manually (ie. create a new col, update
all values, drop the old col). So, there is no reason why this new
attisdropped field shouldn't allow us to implement a full ALTER TABLE/SET
TYPE sort of feature - cool huh?

Chris