Re: Microsoft destroys TPC-C records!

Nuno,

Read it through again - it is describing something that could happen in Oracle and requires application design to implement the business rule.

The example is really saying:

    If you haven't a clue how to define
    and implement the business rules
    properly then its easier to code it
    wrong in Oracle.

and pretending that this is a valid counter-argument

    Writers blocking readers is a bad idea.

In Oracle, to ensure that only one withdrawal of $400 was made, both accounts would
have to be locked for the duration of the transaction. This would have the same apparent effect, of course, as readers blocking writers - but under control of the application and done only when the business rule says that it is necessary.

This one's a laugh of course:-

    The SQL Server database can also be set     up to use the READ UNCOMMITTED ANSI
    standard transaction level, which shows     account balance information even if the     data has not been committed (Option 2     above). In this case the teller sees -$100     in the checking account, and informs the     husband that there are insufficient funds,     which also removes the chance of overdrawing     funds.

Just imagine the scenario -

    Husband asks for 100 dollars
    teller types in 400 dollars, and
    updates the record without commit.

    Wife asks for 400 dollars, gets told     there are insufficient funds and
    hits the roof.

    In the meantime the husband says,
    'No, I wanted £100' - by this time
    it's too late. the other teller has read     the wrong uncommitted data and
    made the wife close the account.

Again - this is a marketing pamphlet
based on making something look like
a benefit by quoting an example that
looks nice superficially, but is actually an application design error.

--

Jonathan Lewis
Yet another Oracle-related web site:  http://www.jlcomp.demon.co.uk

Nuno Souto wrote in message <38eb24f4.11792864_at_news-server>...


>On 5 Apr 2000 01:59:17 GMT, Norris <jcheong_at_cooper.com.hk> wrote:

>

>>See the Locking differences between Oracle and SQLServer

>>http://www.microsoft.com/sql/productinfo/transadvantage.htm

>>

>

>OK, let's give it a try....

>

>

>( - Provides higher accuracy with its "writer-blocks-reader"

>behavior.)

>

>The example provided of the husband-wife is completely FALSE and

>MISLEADING. It is NOT what ORACLE does.

>

>