Data Mining Breaking Changes?

[Dejan Sarka]

BOL 2008, Breaking Changes to Analysis Services Features in SQL Server 2008
(http://msdn.microsoft.com/en-us/library/ms143742.aspx) page says:

Previous versions of Analysis Services support using the MINIMUM_LEAF_CASES
parameter with the Microsoft Decision Trees algorithm, and the
MINIMUM_CLUSTER_CASES parameter with the Microsoft Clustering algorithm.
Since SQL Server 2005 Analysis Services, both of these parameters have been
renamed to MINIMUM_SUPPORT. If these parameters were used in mining models
created using the previous version of Analysis Services , the parameters are
not migrated.

From my tests, in SSAS 2008, they are migrated and even used in processing
the model. BTW, there is definitely a typo in BOL, as you can see from the
copied from BOL referring to SSAS 2005 and not 2008. Nevertheless,
forgetting about the typo, I am interested whether this behavior in SSAS
2008 is intended, is it a bug, undocumented feature, or simply an error in
BOL.

[Bogdan Crivat [MSFT]]

This is a bit more complex. SQL 2000 used MINIMUM_LEAF_CASES (for DT) and
MINIMUM_CLUSTER_CASES (for Clustering)

SQL 2005 exposes MINIMUM_SUPPORT instead of the above parameters in both
cases. The old parameter names are not exposed. However, they are still
supported for backward compatibility. SO the BOL reference to 2005 is not a
typo.

SQL 2008 does not change this behavior: the parameters are not exposed (it
is the MINIMUM_SUPPORT that is exposed), but they are still handled for
backward compatibility in DMX.


The intention is to fully deprecate the old parameter names (..LEAF_CASES
and ...CLUSTER_CASES) and BOL is trying to push users into the new
direction. Consequently, the old names are no longer officially supported,
all new DMX scripts should use the new syntax.

To conclude: it is not a bug, it is an undocumented backward compatibility
feature. BOL is trying to teach the users the "right" direction (which is
supported).
--
--
--
This posting is provided "AS IS" with no warranties, and confers no rights.
Please do not send email directly to this alias. It is for newsgroup
purposes only.

thanks,
bogdan

Post by Dejan Sarka
BOL 2008, Breaking Changes to Analysis Services Features in SQL Server 2008
Previous versions of Analysis Services support using the
MINIMUM_LEAF_CASES
parameter with the Microsoft Decision Trees algorithm, and the
MINIMUM_CLUSTER_CASES parameter with the Microsoft Clustering algorithm.
Since SQL Server 2005 Analysis Services, both of these parameters have been
renamed to MINIMUM_SUPPORT. If these parameters were used in mining models
created using the previous version of Analysis Services , the parameters are
not migrated.
From my tests, in SSAS 2008, they are migrated and even used in processing
the model. BTW, there is definitely a typo in BOL, as you can see from the
copied from BOL referring to SSAS 2005 and not 2008. Nevertheless,
forgetting about the typo, I am interested whether this behavior in SSAS
2008 is intended, is it a bug, undocumented feature, or simply an error in
BOL.
--
Dejan Sarka

[Dejan Sarka]

Thank you again, this makes much sense for me now!

Dejan Sarka

Post by Bogdan Crivat [MSFT]
This is a bit more complex. SQL 2000 used MINIMUM_LEAF_CASES (for DT) and
MINIMUM_CLUSTER_CASES (for Clustering)
SQL 2005 exposes MINIMUM_SUPPORT instead of the above parameters in both
cases. The old parameter names are not exposed. However, they are still
supported for backward compatibility. SO the BOL reference to 2005 is not
a typo.
SQL 2008 does not change this behavior: the parameters are not exposed (it
is the MINIMUM_SUPPORT that is exposed), but they are still handled for
backward compatibility in DMX.
The intention is to fully deprecate the old parameter names (..LEAF_CASES
and ...CLUSTER_CASES) and BOL is trying to push users into the new
direction. Consequently, the old names are no longer officially supported,
all new DMX scripts should use the new syntax.
To conclude: it is not a bug, it is an undocumented backward compatibility
feature. BOL is trying to teach the users the "right" direction (which is
supported).
--
--
--
This posting is provided "AS IS" with no warranties, and confers no rights.
Please do not send email directly to this alias. It is for newsgroup
purposes only.
thanks,
bogdan

Post by Dejan Sarka
BOL 2008, Breaking Changes to Analysis Services Features in SQL Server 2008
Previous versions of Analysis Services support using the
MINIMUM_LEAF_CASES
parameter with the Microsoft Decision Trees algorithm, and the
MINIMUM_CLUSTER_CASES parameter with the Microsoft Clustering algorithm.
Since SQL Server 2005 Analysis Services, both of these parameters have been
renamed to MINIMUM_SUPPORT. If these parameters were used in mining models
created using the previous version of Analysis Services , the parameters are
not migrated.
From my tests, in SSAS 2008, they are migrated and even used in processing
the model. BTW, there is definitely a typo in BOL, as you can see from the
copied from BOL referring to SSAS 2005 and not 2008. Nevertheless,
forgetting about the typo, I am interested whether this behavior in SSAS
2008 is intended, is it a bug, undocumented feature, or simply an error in
BOL.
--
Dejan Sarka