[Top][All Lists]
[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: [Gnumed-devel] Re: Gnumed-devel Digest, Vol 3, Issue 29
From: |
Horst Herb |
Subject: |
Re: [Gnumed-devel] Re: Gnumed-devel Digest, Vol 3, Issue 29 |
Date: |
Tue, 25 Feb 2003 08:13:08 +0100 |
User-agent: |
KMail/1.5 |
On Mon, 24 Feb 2003 02:12 pm, sjtan wrote:
> You are assuming that a 2 tier system is always better than an N-tier
> system. I take Horst's point that a 2 tier system retains the power of
> SQL queries.
Yes, very difficult and very performance expensive to retain tthat power in a
>2 tier system. However, this should not stop us from implementing a "pseudo
3rd tier" *within* an application trying to cleanly separate "businesss
logic" from user interface
> For instance, is it at each page viewing change? What if there are 2
> clinicians entering data and the scope of the transaction boundary is
> patient wide, so that one clinician finishes his entry and then is
> informed his update is aborted because MVCC detects that there is a
> read-write write-read or write-write conflict.
This *cannot* happen:
1.) clinical records are identified by person concerned, time, place and
author. In your case, author is different = two different records
2.) in the rare case where two authors decide to alter an already existing
non-time-sequential record, the data entry widget will of cause issue a
"select for update" statement as soon as a change in content is detected
(first character modified), which locks that particular row for update (but
never for read - that's what MVCC is for).
Horst
- [Gnumed-devel] Re: Gnumed-devel Digest, Vol 3, Issue 29, sjtan, 2003/02/24
- Re: [Gnumed-devel] Re: Gnumed-devel Digest, Vol 3, Issue 29, Karsten Hilbert, 2003/02/24
- Re: [Gnumed-devel] Re: Gnumed-devel Digest, Vol 3, Issue 29, Karsten Hilbert, 2003/02/24
- Re: [Gnumed-devel] Re: Gnumed-devel Digest, Vol 3, Issue 29, Horst Herb, 2003/02/24
- Re: [Gnumed-devel] Re: Gnumed-devel Digest, Vol 3, Issue 29, Hilmar Berger, 2003/02/24
- Re: [Gnumed-devel] Re: Gnumed-devel Digest, Vol 3, Issue 29,
Horst Herb <=