Re: ERROR: tables can have at most 1600 columns

From: Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>
To: Alvaro Herrera <alvherre(at)dcc(dot)uchile(dot)cl>
Cc: Ron St-Pierre <rstpierre(at)syscor(dot)com>, pgsql-general <pgsql-general(at)postgresql(dot)org>
Subject: Re: ERROR: tables can have at most 1600 columns
Date: 2004-06-27 22:48:44
Message-ID: 14554.1088376524@sss.pgh.pa.us
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Alvaro Herrera <alvherre(at)dcc(dot)uchile(dot)cl> writes:
> On Sun, Jun 27, 2004 at 11:11:32AM -0700, Ron St-Pierre wrote:
>> STATEMENT: ALTER TABLE victoria.eodData DROP COLUMN tickDate;
>> ERROR: tables can have at most 1600 columns
>> STATEMENT: ALTER TABLE victoria.eodData ADD COLUMN tickerID INTEGER;
>> ERROR: tables can have at most 1600 columns

> Have you done the DROP COLUMN/ADD COLUMN cycle to this table more than,
> say, 1500 times? Because a dropped column is actually only hidden from
> the user, but it's still present to the system and it will still affect
> the 1600 limit.

That is a good theory, but it doesn't quite explain why Ron's getting
the error from DROP COLUMN --- AFAICS, the places that would issue such
an error won't get called in that path.

I tried to reproduce this and could not: after 1600 cycles of adding and
dropping a column, I did indeed start to get "tables can have at most
1600 columns" from ADD, but DROP continued to behave normally.

Ron, are you sure these errors were coming from the DROPs and not only
the ADDs? Can you exhibit a test case?

regards, tom lane

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