RE: ALTER TABLE DROP COLUMN

At 01:43 PM 6/10/00 +0900, Hiroshi Inoue wrote:
>> -----Original Message-----
>> From: pgsql-hackers-owner@hub.org 
>> [mailto:pgsql-hackers-owner@hub.org]On Behalf Of Bruce Momjian
>> 
>> Seems we have 4 DROP COLUMN ideas:
>> 
>>     Method                                                  Advantage
>>     -----------------------------------------------------------------
>> 1    invisible column marked by negative attnum        fast
>> 2    invisible column marked by is_dropped column        fast
>> 3    make copy of table without column            col removed
>> 4    make new tuples in existing table without column    col removed
>> 
>> Folks, we had better choose one and get started.  

Oracle gives you the choice between the "cheating" fast method(s) and
the "real" slow (really slow?) real method.

So there's at least real world experience by virtue of example by
the world's most successful database supplier that user control
over "hide the column" and "really delete the column" is valuable.

It really makes a lot of sense to give such a choice.  If one
does so by "hiding", at a later date one would think the choice
of "really deleting" would be a possibility.  I don't know if
Oracle does this...

If not, they might not care.  In today's world, there are bazillions
of dollars for Oracle to scoop up from users who could just as easily
be PG users - all those "we'll fail if don't IPO 'cause we'll never
have any customers" database-backed websites :)



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