ADP Ready for Prime Time?

[Neil Ginsberg]

A while back I posted a message re. using an ADP file with a SQL Server back
end as opposed to MDB file with linked tables, thinking that the ADP file
would be less problematic. The input I got was that the ADP would be just
as, if not more, problematic; that ADO is far more limited than DAO,
requiring a lot of workarounds; and that it would be better to stay with a
seasoned MDB file than to switch to an ADP.

The database in question was inherited by me from someone else who
implemented things in a less than ideal way, and he, himself, converted it
from an existing database in another application. The database needs to be
revamped, and we are looking to rebuild it from the ground up with
additional functionality. So now the question is not staying with a seasoned
MDB as opposed to a new ADP; but, rather, which would be better for working
with a SQL Server back end, an MDB or ADP file?

Obviously if we go with an MDB file we can reuse many of the DAO routines,
as appropriate. But the main concern here is performance: which one will
provide the better performance, better data access, fewer strange anomalies,
and so on. Development time isn't the main concern.

The database currently relies in part on DAO and in part on stored
procedures. Obviously moving more towards stored procedures would be better,
but there will probably still be a significant amount of code in the front
end.

Any thoughts re. MDB vs. ADP or anything else related to this would be
appreciated.

Thanks,

Neil

 

[Steve Jorgensen]

A while back I posted a message re. using an ADP file with a SQL Server back
end as opposed to MDB file with linked tables, thinking that the ADP file
would be less problematic. The input I got was that the ADP would be just
as, if not more, problematic; that ADO is far more limited than DAO,
requiring a lot of workarounds; and that it would be better to stay with a
seasoned MDB file than to switch to an ADP.

The database in question was inherited by me from someone else who
implemented things in a less than ideal way, and he, himself, converted it
from an existing database in another application. The database needs to be
revamped, and we are looking to rebuild it from the ground up with
additional functionality. So now the question is not staying with a seasoned
MDB as opposed to a new ADP; but, rather, which would be better for working
with a SQL Server back end, an MDB or ADP file?

Obviously if we go with an MDB file we can reuse many of the DAO routines,
as appropriate. But the main concern here is performance: which one will
provide the better performance, better data access, fewer strange anomalies,
and so on. Development time isn't the main concern.

It's not just the develompment time, it's the unpredictability of runtime
behavior. It's just fastly harder to deliver verifiably high quality code
with ADPs. They're too much of a hodge podge of hastily patched together
kludges. ADPs and ADO also introduce at least as many performance bottlenecks
as performance improvments, and well-designed MDB client/server apps have been
known to perform really well.

The database currently relies in part on DAO and in part on stored
procedures. Obviously moving more towards stored procedures would be better,
but there will probably still be a significant amount of code in the front
end.

That's obvious, but not necessarily correct. Access works quite well using
forms bound to DAO recordsets on linked tables. if you deviate from that, you
might as well scrap Access altogether and implement custom GUIs in something
like C# or Java - of course, that might really be your best answer if time is
not an issue.

With respect to stored procedures performing universally better than Access
queries of linked tables, it's simply not the case. In most cases, an Access
query generates a prepared statement on the server side which functions much
like a stored procedure would. When the server sees the same prepared
statement signature again later on, it will realize it can use the same query
plan it computed for the statement previously - just like a stored procedurem
only without the headaches of being unable to update via an Access bound form.

Any thoughts re. MDB vs. ADP or anything else related to this would be
appreciated.

It's easier to get higher reliability and good performance with an MDB than an
ADP - period. If time is not an issue, scrap Access altogether and write
hand-optimized code in a "real" programming language.

 

[altacct]

It's not just the develompment time, it's the unpredictability of runtime

behavior.

[snip]
It's easier to get higher reliability and good performance with an MDB than an
ADP - period.

Steve,

What are the issues you're talking about here? Or can you point me to a
link that talks about some of them (if they've been discussed
extensively)? I haven't been around the CDMA 'hood for a while; I know
there are plenty of people who argue, and I agree with them, that
learning ADO because it's new doesn't make any sense, but I don't
remember reading much that talks about ADPs being inherintly more prone
to falling over at run time, or inherintly requiring more development
time (other than learning ADO).

This is in no way a troll or a challenge. I've been working on a
project that uses a MS SQL Server back end and an ADP front for the
last seven months, and I've run into very few things that I hadn't seen
in an MDB. Or at least that's my impression--maybe I'm just seeing
trees, though.

Jeremy

PS: I will tell you about the coolest run-time bug I've ever seen in
Access, though. It only happened in a2k3, and only with one particular
datasheet-viewed subform. And only very rarely and unpredicatbly. But
on one of our forms, if you got lucky, you could resize one of the
subforms by grabbing the scroll bar. At run time. We have a lot of
people using the database, and we've never gotten a report of anyone
finding this particular bug. But it sure scared the heck outta me when
I saw it!

 

[Steve Jorgensen]

It's not just the develompment time, it's the unpredictability of runtime

behavior.

[snip]
It's easier to get higher reliability and good performance with an MDB than an
ADP - period.

Steve,

What are the issues you're talking about here? Or can you point me to a
link that talks about some of them (if they've been discussed
extensively)? I haven't been around the CDMA 'hood for a while; I know
there are plenty of people who argue, and I agree with them, that
learning ADO because it's new doesn't make any sense, but I don't
remember reading much that talks about ADPs being inherintly more prone
to falling over at run time, or inherintly requiring more development
time (other than learning ADO).

This is in no way a troll or a challenge. I've been working on a
project that uses a MS SQL Server back end and an ADP front for the
last seven months, and I've run into very few things that I hadn't seen
in an MDB. Or at least that's my impression--maybe I'm just seeing
trees, though.

Well, for one thing, ADPs have a habit of making certain multi-table queries
uneditable. The first version of a query may be editable, but after some
random and seemingly trivial change in the query itself or afger the next
Access service pack or MDAC upgrade, it becomes uneditable again, and the
tweaking process starts all over again. I've finally gotten to the point
where I don't even try to use multi-table queries on bound forms in an ADP.
Either, I use combo boxes as lookups for data in related tables (uh yeah,
that'll help performance), or have to use separate forms for adding/editing
which is more clicks and work hassle for the user as well as more duplication
of form design elements.

For another thing, there is a bug that was supposedly fixed, but actually
isn't in which sometimes an ORDER BY clause in a subform or subreport causes
an error. To fix it, it is necessary to remove the table name qualifier from
the expression in the ORDER BY clause. Of course, the query builder always
puts the table qualifiers on, and it's never obvious what's broken without
some digging.

In ADPs, any time you do anything slightly out of the ordinary in a
server-side query, the ADP gets confused. For instance, in my MDBs, sometimes
I like to have a view that references a table in another database on the
server. I do this, for instance, to put tables frequently used to hold
temporary data in a database with TRUNCATE LOG ON CHECKPOINT so my backups
aren't filled mostly with irrelevant adding and deleting of temporary data.
When you try to bind an ADP to this, it gets really confused beacause ADO is
smart enough to try to look at the underlying tables, but not smart enough to
look at them in another database on the server.

The ADP looking behind your stored procedures and views also makes it hard to
do things that work fine in an MDB such as using a view for security where the
user has permissions granted via the view that they don't haveon the tables
directly. If you know the issue and are -very- careful, you can work around
this. This is in the category of ADPs trying to think for you and thus making
it very hard to use what should be typical rule enforcement on the back-end.

I can't remember all the other issues right now, but I remember that there are
several more.

 

[lylefair]

Any thoughts re. MDB vs. ADP or anything else related to this would be
appreciated.

If you bind your forms then your users must have SQL table permissions.
If they have table permissions what is to prevent them from using these
permissions directly on the table, in your database or another?
One can prevent this by using application roles. Unfortunately ADPs and
application roles combined are a cruel joke, because ADPs have various
connections for various interfaces and one cannot predict what
connection will be used where.
And if you don't bind your forms why use Access, ... for its limited
forms, its bizarre idiosyncracies, its memory glut, its archaic
scripting language? Maybe for its reports? MAYBE!

Access is dead. It's fine with JET; but JET has been retired and is
rusting out slowly on one of those big California desert airfields. As
a front end for other db engines it's a joke, a bad joke.

What are those lines from "Red Rubber Ball"?
"I bought my ticket with my tears,
That's all I'm gonna spend."

 

[Larry Linson]

There seem to be indications that Jet isn't quite "rusting away" despite it
having once been declared "in maintenance mode" -- it has been updated since
that declaration and Jet-ODBC-Server is now recommended over
ADP-ADODB-Server by knowledgeable Microsoft insiders.

In fact, one poster in CDMA said that Microsoft had told him that ADP-ADO
was being "deprecated" in the next version. But I have not personally seen
such a statement from Microsoft.

The old crystal ball is cloudy, at best, but it's clear from what Microsoft
has publicly stated that there is going to be another release of Microsoft
Office and Access is going to be part of it.

Larry Linson
Microsoft Access MVP

 

[Steve Jorgensen]

There seem to be indications that Jet isn't quite "rusting away" despite it
having once been declared "in maintenance mode" -- it has been updated since
that declaration and Jet-ODBC-Server is now recommended over
ADP-ADODB-Server by knowledgeable Microsoft insiders.

In fact, one poster in CDMA said that Microsoft had told him that ADP-ADO
was being "deprecated" in the next version. But I have not personally seen
such a statement from Microsoft.

The old crystal ball is cloudy, at best, but it's clear from what Microsoft
has publicly stated that there is going to be another release of Microsoft
Office and Access is going to be part of it.

Larry Linson
Microsoft Access MVP

My concern is that since it seems clear that Access will lag the rest of MS
Office in terms of implementation as a .NET base app, it will get increasingly
orphaned by developers migrating from VB/VBA development as advances in the
..NET UI technology simultaneously narrow the functionality gap with Access in
terms of things like easy reporting and continuous bound forms.

If that is the trend, it might be better to be leading it than following it.

 

[Larry Linson]

Well, Steve... for a "nice little desktop database", Access has given us a
"pretty good ride"... it was first released in October 1992, so it has
lasted over 12 years, so far, and it's not nearly dead yet.

But, even if it were... 12 years is a significant lifetime for a software
product.

(And, another thing, I made a good living just out of Access for most of
those 12 years. That, too, is impressive for a "nice little desktop
database". I am convinced it was so much better than expected that it
surprised even its developers.)

Larry

My concern is that since it seems clear that Access will lag the rest of MS
Office in terms of implementation as a .NET base app, it will get increasingly
orphaned by developers migrating from VB/VBA development as advances in the
.NET UI technology simultaneously narrow the functionality gap with Access in
terms of things like easy reporting and continuous bound forms.

If that is the trend, it might be better to be leading it than following

it.

 

[Steve Jorgensen]

Absolutely - Access has been an incredible tool, and still is.

 

[Guest]

I Think access is a very good desktop tool. But not in Multi user environment.
Yet still it is very good tool for agile programming. No other front end
gives the flexibility to generate quick reports in an easy manner. So it is
very good tool for datacenters.

But as a developer, I always have following options:

Why should I use troublesome adp forms insert, delete and updates when i can
do the same with asp.net with less effort.

Why should i work on access reports, when sql server reports are more crispy

why should I reley on jet when everything is done by sql server

But I love access, I dont know why?

Can't there be access.net with out bugs

R.D

 

[Jim Rand]

Thank you for the discussion about ADP because I was considering using it
but now realize that what I have is superior to both ADP and MDB's with
linked tables.

Think outside of the box. Linked tables across the network are bad, bad,
bad, bad.... So don't use them.

What is the fastest way to retrieve data using an Access MDB? A query pass
thru. Can you bind a form to a QPT? Yes. What happens if you try to update a
field in a form bound to a QPT? Hmm - not good - it's not updatable.

Let's see. Can you create a query (make table or append) that uses the QPT
as its source? Yes. Hmm. Now you have a way to get data from the backend to
a front-end local table very quickly. Can you bind a form to the local
table? Yes. What happens to the backend data when you update the front-end
table through the form? Nothing. That's not good. Oh but wait!

What if you delegate the AfterUpdate, AfterInsert, Delete and
AfterDelConfirm events to a common form handler that references a VB DLL
that repeats the updates, inserts and deletes to the backend? In the length
of time for the user to scroll from the updated row to the next row, the
backend is updated even though there is no link to the backend.

What you wind up with is a very very very fast 2 tier client server
solution. Access is used on the front end for programming and for managing
disconnected datasets (makes you think about ADO.NET). If your really
skillful, you can gracefully manage concurrency conflicts (hint: think
timestamps) and deal with autoincrement keys (stored procedures for inserts
that pass back @@IDENTITY). You could even create a reusable table driven
architecture that completely hides the complexity of the data marshalling.

Again, the discussions about ADP versus MDB's has been great -- particularly
the part about how ADP's manage connections.

Jim Rand

 

[Vadim Rapp]

Hello Neil:
You wrote in conference
comp.databases.ms-access,microsoft.public.access.adp.sqlserver,microsoft.public.access.odbcclientsvr
on Tue, 18 Jan 2005 07:38:50 GMT:

NG> Any thoughts re. MDB vs. ADP or anything else related to this would be
NG> appreciated.

You will write the best code in the environment where you are more
proficient.

If you are equally proficient in MDB and ADP, probably ADP is better because
it's closer to today's approach.

If you choose ADP, one word of advise will be this: avoid using ADO
directly. Don't force Access into using ADO; rather, have Access do the job
with its own means - make everything bound, no "manual" manipulations with
the data; and don't ever touch form.recordset.


Vadim Rapp

 

[Steve Jorgensen]

Hello Neil:
You wrote in conference
comp.databases.ms-access,microsoft.public.access.adp.sqlserver,microsoft.public.access.odbcclientsvr
on Tue, 18 Jan 2005 07:38:50 GMT:

NG> Any thoughts re. MDB vs. ADP or anything else related to this would be
NG> appreciated.

You will write the best code in the environment where you are more
proficient.

If you are equally proficient in MDB and ADP, probably ADP is better because
it's closer to today's approach.

If you choose ADP, one word of advise will be this: avoid using ADO
directly. Don't force Access into using ADO; rather, have Access do the job
with its own means - make everything bound, no "manual" manipulations with
the data; and don't ever touch form.recordset.

Your 2 statements seem to contradict each other. You say to avoid using the
API, but you say to use ADO because it's closer to today's approach (I assume
you mean because it uses ADO by default).

I can't agree with that. If you mostly avoid the API, it's better to use the
more mature and reliable Access project type, and that's the MDB hands-down.
Furthermore, I often use ADO in MDB applications, so the MDB doesn't get in
the way on that score either.

Furthermore, I have had notoriously poor luck with ADPs usaing purely bound
data designs because so many things that are not a problem in MDBs are so
touchy in ADPs. I have to add more complexity and write more code to work
around these things, so ADPs certainly don't help facilitate the "everything
bound approach".

 

[Sylvain Lafontaine]

In its conception, ADP is a far better technologie then MDB with linked
tables and sql passthrough for interfacing with a SQL-Server and there is
simply no comparaison between these two at their design level. Even if it's
working properly and without any bug, MDB' linked tables and sql passthrough
can only be seen, at their best, as some sort of strange kludge without any
real future.

The decision of replacing MDB linked tables with ADP was taken sometime like
five years ago and was part of the Microsoft' DNA (Distributed Network
Application). However, while MS was still working on developping ADP (and
DNA), they have took the decision of abandonning DNA (a failure) in favor of
the .NET technologies. For interfacing with databases and displaying datas,
MDB, ADP and DNA (and others) are primary based on Recordsets (either DAO or
ADO) while .NET are based on Datasets (and DataReaders).

We don't know the futur of Recordsets (DAO or ADO) in the mind of Microsoft
but obviously, the development of ADP has been abruptly stopped while it
was still unfinished and full of bugs. This doesn't look good for the
future of Recordsets. Even if it's a lesser technologie, MS has decided in
favor of MDB with linked tables over ADP simply because it have been
finished many years ago and have most of its bugs ironed out since a long
time.

The most likely outcome is that they will continue to finish the .NET
framework, then integrate Access with it and after that, DAO, ADO and
Recordsets will follow ADP in the little basket. In the meantime and IMHO,
the best decision for a *new project* is not to choose MDB over ADP or the
other way but simply to forgot about these two and to go directly to the
..NET framework; as both MDB and ADP now appears to be dead ends in the near
futur (probably with the next release of Access, my guest being something
like the autumn of 2006).

S. L.

 

[J. Clay]

Everyone seems to come down hard on ADPs and I just don't agree with them.
I converted our system to ADP/SQL three years ago and my experience has been
positive. I think the biggest issue is that you need to change your
paradigm and think in a single
record mentality on forms. The system I originally developed in A97 and are
up to A2002 and it has continually grown in functionality and complexity.
At this point I have over 20,000 lines of VBA code along with the 100+
stored procedures.

The ability to work directly from Access in stored procedures, views and
database diagrams is a big plus. I still use SQL Enterprise manager on
occasion, but only for specific reasons.

The biggest change I made is that I DO NOT use the built in navigation. I
know at first thought this doesn't seem right, since that is one of the
benefits of working in Access. Instead, I use a stored procedure as the
record source for ALL of my main forms and use input parameters. This way,
only 1 record is returned by the server no matter what. This works very
well in house and has the benefit of 1) disabling the mouse wheel and 2)
give relatively good and usable performance over a WAN.

Anyway, I personally like the ADP format and hope that it is at least
maintained and enhanced.

Jim

 

[Steve Jorgensen]

....

Anyway, I personally like the ADP format and hope that it is at least
maintained and enhanced.

Well, with a few minor improvements and fixes, I'd almost agree that ADPs are
a good thing. If it worked correctly to bind a form to a disconnected ADO
recordset, Access would actually allow one to easily scale a 2-tier
RAD-developed app into a full 3-tier app with a VB business logic layer. As
it is, that's a no go because attempting to edit a bound, disconnected
batch-updatable recordset first does not work, then usually ends up crashing
Access.

Regarding to abandonment of the built-in continuous form capability, that
seems to me to throw away one of the 2 biggest reasons for bothering to use
Access which are continuous forms and great reporting capabilities. In that
case, why not use a language like C# that gets in the way less than VB does?
After all, .NET studio has a perfectly good editor for bound forms (yes, I
know the combo boxes are not as nice).

 

[Larry Linson]

I Think access is a very good desktop
tool. But not in Multi user environment.

Access is an _excellent_ tool for: end users, power users, individual users,
multiuser environments, and as a client to various server databases.

Why should I use troublesome adp
forms insert, delete and updates

That is a very good question -- why, indeed, would you use ADP when many
formerly-enthusiastic knowledgeable users (e.g. Lyle Fairfield) had so many
problems that they have abandoned it and when knowledgeable Microsoft
insiders now recommend using the traditional MDB-DAO-Jet-serverDB over the
alternative of using ADP-ADODB-MSSQLServer?

when i can do the same with asp.net
with less effort.

Even so, my experience with ADPs does not apparently match yours. I prefer
MDB/MDE to ADP/ADE, but, for client-server environments ADP seems much
easier than any .NET tools. It is fraught with problems of various kinds,
but "being harder than .NET" isn't one of them.

"ASP.NET" is, by definition, for creating web-based applications; Aceess
ADPs cannot, by definition, create web-based apps, but only client-server
apps -- they are not at all comparable.

Why should i work on access reports,
when sql server reports are more crispy

"Crispy"? Access reports are simple, straightforward, and very capable.
Strictly speaking, SQL Server does not even DO reports. If you are writing
about SQL Server Reporting Services, that is a separate (and
separately-priced, not inexpensive, BTW) product. It is also very capable.

why should I reley on jet when
everything is done by sql server

Not "everything is done by SQL server". SQL Server is not even part of the
vast majority of Access database applications. If you are doing
client-server applications, the kind in which Access is such a great tool
for creating clients, you'd use Jet to link to SQL Server via ODBC, but you
could also use it to improve performance by maintaining infrequently-changed
data in local lookup tables.

But I love access, I dont know why?

Perhaps you were taking advantage of many of the great features of Access,
and didn't even realize it?

Can't there be access.net with out bugs

Software has been around for something over 50 years. As far as I know,
there's been no software product or package anywhere near the size of Access
that was _ever_ bug-free. I suppose it is possible, but I don't think it is
likely that you'll see such in the near future, either.

Larry Linson
Microsoft Access MVP

 

[Vadim Rapp]

Hello Steve:
You wrote in conference
comp.databases.ms-access,microsoft.public.access.adp.sqlserver,microsoft.public.access.odbcclientsvr
on Thu, 20 Jan 2005 21:41:29 -0800:

SJ> On Thu, 20 Jan 2005 23:12:08 -0600, "Vadim Rapp"
<[email protected]>
SJ> wrote:

SJ>> If you are equally proficient in MDB and ADP, probably ADP is better
SJ>> because it's closer to today's approach.
SJ>>
SJ>> If you choose ADP, one word of advise will be this: avoid using ADO
SJ>> directly. Don't force Access into using ADO; rather, have Access do
SJ>> the job with its own means - make everything bound, no "manual"
SJ>> manipulations with the data; and don't ever touch form.recordset.

SJ> Your 2 statements seem to contradict each other. You say to avoid
SJ> using the API, but you say to use ADO because it's closer to today's
SJ> approach (I assume you mean because it uses ADO by default).


Not at all. I did not even mention the word API, so I assume you meant ADO.

I say to use ADP because ADP is based on ADO, which is closer to today's
approach, also it's more "direct" way to work with sql server. But not to
use ADO directly. Use Access/ADP methods, and Access will use ADO as it
wants to.


SJ> Furthermore, I have had notoriously poor luck with ADPs usaing purely
SJ> bound data designs because so many things that are not a problem in
SJ> MDBs are so touchy in ADPs.

As I wrote, the key to success is using one tool that you are most
proficient with. If you are using two very related API's, you are doomed for
the problems, because you can't avoid applying one approach to another API.
I bet that if you started using _only_ ADP, without even touching MDB, in
several weeks you would suddenly find that you and Access have adjusted to
each other, and the problems mysteriously dissolved. Your sub-conscience
would learn to choose the good (for the ADP) methods and avoid the bad ones.
And then in several more weeks, given the opportunity, you would find that
so many things that are not a problem in ADPs are so touchy in MDBs.

Vadim

 

[Guest]

ADPs are ready for primetime.

but they're difficult to implement, especially things like this:

1) forms against views is difficult/unpredictable
2) stored procs bind well to form, but it isn't very well documented
3) sql server doesn't have a crosstab query (yet)

hth

 

[Guest]

views are a pain to update

so basically use base tables

and get this

1) only load a single record at a time and this should cut down on
complexity

It's not just the develompment time, it's the unpredictability of runtime

behavior.

[snip]
It's easier to get higher reliability and good performance with an MDB than an
ADP - period.

Steve,

What are the issues you're talking about here? Or can you point me to a
link that talks about some of them (if they've been discussed
extensively)? I haven't been around the CDMA 'hood for a while; I know
there are plenty of people who argue, and I agree with them, that
learning ADO because it's new doesn't make any sense, but I don't
remember reading much that talks about ADPs being inherintly more prone
to falling over at run time, or inherintly requiring more development
time (other than learning ADO).

This is in no way a troll or a challenge. I've been working on a
project that uses a MS SQL Server back end and an ADP front for the
last seven months, and I've run into very few things that I hadn't seen
in an MDB. Or at least that's my impression--maybe I'm just seeing
trees, though.

Well, for one thing, ADPs have a habit of making certain multi-table queries
uneditable. The first version of a query may be editable, but after some
random and seemingly trivial change in the query itself or afger the next
Access service pack or MDAC upgrade, it becomes uneditable again, and the
tweaking process starts all over again. I've finally gotten to the point
where I don't even try to use multi-table queries on bound forms in an ADP.
Either, I use combo boxes as lookups for data in related tables (uh yeah,
that'll help performance), or have to use separate forms for adding/editing
which is more clicks and work hassle for the user as well as more duplication
of form design elements.

For another thing, there is a bug that was supposedly fixed, but actually
isn't in which sometimes an ORDER BY clause in a subform or subreport causes
an error. To fix it, it is necessary to remove the table name qualifier from
the expression in the ORDER BY clause. Of course, the query builder always
puts the table qualifiers on, and it's never obvious what's broken without
some digging.

In ADPs, any time you do anything slightly out of the ordinary in a
server-side query, the ADP gets confused. For instance, in my MDBs, sometimes
I like to have a view that references a table in another database on the
server. I do this, for instance, to put tables frequently used to hold
temporary data in a database with TRUNCATE LOG ON CHECKPOINT so my backups
aren't filled mostly with irrelevant adding and deleting of temporary data.
When you try to bind an ADP to this, it gets really confused beacause ADO is
smart enough to try to look at the underlying tables, but not smart enough to
look at them in another database on the server.

The ADP looking behind your stored procedures and views also makes it hard to
do things that work fine in an MDB such as using a view for security where the
user has permissions granted via the view that they don't haveon the tables
directly. If you know the issue and are -very- careful, you can work around
this. This is in the category of ADPs trying to think for you and thus making
it very hard to use what should be typical rule enforcement on the back-end.

I can't remember all the other issues right now, but I remember that there are
several more.