From: Markus E Leypold <development-2006-8ecbb5cc8aREMOVETHIS@ANDTHATm-e-leypold.de>
Subject: Re: Generic Package
Date: Fri, 27 Apr 2007 14:52:44 +0200
Date: 2007-04-27T14:52:44+02:00 [thread overview]
Message-ID: <tjirbif083.fsf@hod.lan.m-e-leypold.de> (raw)
In-Reply-To: ozslghlwuydt$.1t30ht6ytimwi$.dlg@40tude.net
"Dmitry A. Kazakov" <mailbox@dmitry-kazakov.de> writes:
> On Fri, 27 Apr 2007 13:11:30 +0200, Georg Bauhaus wrote:
>
>> On Fri, 2007-04-27 at 11:00 +0200, Dmitry A. Kazakov wrote:
>>> On Thu, 26 Apr 2007 22:52:58 +0100, Simon Wright wrote:
>>>
>>>> "Dmitry A. Kazakov" <mailbox@dmitry-kazakov.de> writes:
>>>>
>>>>> You cannot iterate a relational table, because there is no order
>>>>> defined on it.
>>>>
>>>> Why would that stop me iterating over all the rows?
>>>
>>> Because iterating presumes following an order.
>>
>> Any real table in an existing computer has a "natural"
>> ordering suitable for iterating an operation for all
>> elements: data in a real computer can be uniquely identified.
>
> No this is wrong even on a real computer. The DB engine could shuffle the
> rows asynchronously to your application. There could be other applications
> playing with the table. The table might spread over memories of several
> computers and different levels cashes. You have to bring transactions,
> replications and other synchronizing stuff to make any sense out of
> "natural order."
>
>> The fact that the ordering is hidden behind the functional
>> Iterate abstraction doesn't make it go away for any
>> snapshot of rows.
>
> It does. Semantically, table /= a snapshot of. That is.
>>>>> You cannot iterate a relational table, because there is no order
>>>>> defined on it.
You know, I'm iterating over relational tables (or what I thought were
relational tables) all the time. This basically is the way most of the
interfaces to RDBSs I use work: Executing a query gives you a result
cursor, which you can use to extract the result row by row. The actual
sequence in which they come is unspecified and up to the database
engine if I haven't specified sorting in my query (which I don't in
many circumstances where I only want to get at a set of tuples but
don't require any specific order).
Are you telling me I've been hallucinating and that I have been NOT
iterating over those tables (because one cannot)? Or do you intend to
come up with a "smart" definition of "iterating" or "relational table"
now, which -- contrary to everyones expectations and common
understanding -- will somehow exclude my scenario from the definition?
<Shaking my head>
Regards -- Markus
next prev parent reply other threads:[~2007-04-27 12:52 UTC|newest]
Thread overview: 84+ messages / expand[flat|nested] mbox.gz Atom feed top
2007-04-25 22:15 Generic Package andrew.carroll
2007-04-26 0:07 ` Jeffrey R. Carter
2007-04-26 7:46 ` Markus E Leypold
2007-04-26 6:02 ` Martin Krischik
2007-04-26 7:57 ` Dmitry A. Kazakov
2007-04-26 15:31 ` andrew.carroll
2007-04-26 16:07 ` Georg Bauhaus
2007-04-26 19:40 ` andrew.carroll
2007-04-26 20:01 ` Georg Bauhaus
2007-04-26 18:54 ` Dmitry A. Kazakov
2007-04-26 21:52 ` Simon Wright
2007-04-27 9:00 ` Dmitry A. Kazakov
2007-04-27 11:11 ` Georg Bauhaus
2007-04-27 12:06 ` Dmitry A. Kazakov
2007-04-27 12:52 ` Markus E Leypold [this message]
2007-04-27 14:10 ` Georg Bauhaus
2007-04-27 14:16 ` Dmitry A. Kazakov
2007-04-27 21:44 ` Georg Bauhaus
2007-04-28 7:38 ` Dmitry A. Kazakov
2007-04-28 17:50 ` Simon Wright
2007-04-28 21:04 ` Ray Blaak
2007-04-29 16:33 ` Markus E Leypold
2007-04-27 19:44 ` Simon Wright
2007-04-27 20:34 ` Dmitry A. Kazakov
2007-04-27 21:16 ` Simon Wright
2007-04-28 7:36 ` Dmitry A. Kazakov
2007-04-27 11:43 ` Markus E Leypold
2007-04-28 17:35 ` Dmitry A. Kazakov
2007-04-28 23:06 ` Georg Bauhaus
2007-04-29 8:19 ` Dmitry A. Kazakov
2007-04-29 15:10 ` (see below)
2007-04-29 17:48 ` Dmitry A. Kazakov
2007-04-29 22:36 ` (see below)
2007-04-30 6:58 ` Dmitry A. Kazakov
2007-04-30 9:59 ` Markus E Leypold
2007-04-30 10:01 ` Markus E Leypold
2007-04-30 10:36 ` Georg Bauhaus
2007-04-30 10:40 ` Georg Bauhaus
2007-04-30 12:14 ` Dmitry A. Kazakov
2007-04-30 14:57 ` (see below)
2007-04-30 10:30 ` Georg Bauhaus
2007-04-30 12:16 ` Dmitry A. Kazakov
2007-04-30 14:48 ` Georg Bauhaus
2007-04-30 16:29 ` Dmitry A. Kazakov
2007-04-30 17:24 ` Georg Bauhaus
2007-04-30 18:54 ` Dmitry A. Kazakov
2007-04-30 19:29 ` Simon Wright
2007-04-30 20:04 ` Dmitry A. Kazakov
2007-05-01 0:11 ` Markus E Leypold
2007-05-01 9:02 ` Georg Bauhaus
2007-05-01 10:19 ` Dmitry A. Kazakov
2007-05-01 13:42 ` Georg Bauhaus
2007-05-01 17:16 ` Dmitry A. Kazakov
2007-05-01 19:14 ` Randy Brukardt
2007-05-01 20:14 ` Dmitry A. Kazakov
2007-05-02 7:52 ` Markus E Leypold
2007-05-02 8:06 ` Markus E Leypold
2007-05-03 0:37 ` Randy Brukardt
2007-05-03 8:36 ` Markus E Leypold
2007-05-03 23:16 ` Randy Brukardt
2007-05-04 0:15 ` Markus E Leypold
2007-05-01 21:41 ` Georg Bauhaus
2007-05-02 6:57 ` Ray Blaak
2007-05-02 8:22 ` Markus E Leypold
2007-05-02 8:07 ` Markus E Leypold
2007-05-02 10:29 ` Dmitry A. Kazakov
2007-05-02 11:48 ` Georg Bauhaus
2007-05-02 11:50 ` Georg Bauhaus
2007-05-02 13:12 ` Dmitry A. Kazakov
2007-05-02 14:21 ` Markus E Leypold
2007-05-03 18:27 ` Georg Bauhaus
2007-05-03 19:07 ` Dmitry A. Kazakov
2007-05-03 19:49 ` Markus E Leypold
2007-04-29 16:26 ` Markus E Leypold
2007-04-26 21:50 ` Simon Wright
2007-04-27 4:45 ` Jeffrey R. Carter
2007-04-27 7:45 ` Martin Krischik
2007-04-27 22:54 ` Georg Bauhaus
2007-04-30 20:13 ` Matthew Heaney
2007-04-26 20:48 ` andrew.carroll
-- strict thread matches above, loose matches on Subject: below --
2003-12-02 23:15 Mr. J.
2003-12-03 9:31 ` Dmitry A. Kazakov
2003-12-02 23:13 generic package Ratson Janiv
2003-12-03 17:39 ` Stephen Leake
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