Re: Problem with rownum

From: DA Morgan <damorgan_at_x.washington.edu>
Date: Thu, 13 Jan 2005 22:37:08 -0800
Message-ID: <41e7688a$1_1@127.0.0.1>

Andy Hassall wrote:

> On Thu, 13 Jan 2005 16:07:48 -0800, DA Morgan <damorgan_at_x.washington.edu>
> wrote:
>
>

>>Andy Hassall wrote:
>>
>>>On Thu, 13 Jan 2005 14:27:04 -0800, DA Morgan <damorgan_at_x.washington.edu>
>>>wrote:
>>>
>>>>Graeme D wrote:
>>>>
>>>>
>>>>>I don't understand why oracle doesn't have something like LIMIT x,x liek 
>>>>>there is in MySQL... any ideas?
>>>>
>>>>I don't understand why MySQL doesn't have full relational integrity and
>>>>the ability to perform transactional recovery ... any ideas?
>>>
>>> Yes it does, and yes it can. Perhaps you're still only considering the
>>>features of older versions, or haven't read the manual recently?
>>>
>>> A more helpful reply would be to point out how rownum in Oracle is determined,
>>>i.e. it's done before a sort, so an equivalent to MySQL's limit would involve a
>>>sorted subquery.
>>
>>Are you using the obfuscation toolkit? How in MySQL can you recover a
>>corrupt database at the transaction level? I may be behind by the latest
>>release but not more than that.

>
>
> There's the binary log, which looks remarkably similar to a somewhat primitive
> version of Oracle redo/archive logs:
>
> http://dev.mysql.com/doc/mysql/en/Binary_log.html
>
> There's then a description of rolling forwards using the binary log:
>
> http://dev.mysql.com/doc/mysql/en/Backing_up.html
>
> And on the other point, referential integrity has been supported since 3.2 -
> 4.1 is now the current release.
>
> MySQL certainly used to deserve massive amounts of scorn poured on it due to
> lack of even basic transactions, let alone foreign keys, but it appears to have
> progressed far enough to be taken seriously for certain circumstances. It's
> even got Oracle-style multi-versioned non-locking consistent-reads now.
>
> It still has various severe flaws of course, and given the choice I stick by
> Oracle, but they've been taking fairly big bites out of some of the main
> objections.

Don't get me wrong MySQL has its place and I have used it where appropriate but a line-of-business transactional system? Not while I value what little reputation I have.

Got any problems with this: http://sql-info.de/mysql/gotchas.html in terms of accuracy?

When I refer to referential integrity I don't mean the fact that they finally figured out what it is but rather the full purpose it serves in a "real" database. Take a look, for example, at item 3.2 at the link above. That to me is not referential integrity.

-- 
Daniel A. Morgan
University of Washington
damorgan_at_x.washington.edu
(replace 'x' with 'u' to respond)

Received on Fri Jan 14 2005 - 00:37:08 CST