Monday, March 03, 2008

Monday morning random rambling...

Now that caffeine is taking effect: I attended the Heroes Happen Here event in Toronto last week. The event was fun in general, lots of marketing going on so the developers get really biased, towards Microsoft technologies, of course...
Not that this is necessarily a bad thing, as long as you keep your mind open to what's going on on other development niches and keep the constructive criticism.
I enjoyed the developer tracks in the morning but most of all I enjoyed two architecture presentations, they were light and fun, not too deep in content though, but very refreshing. Here are the blogs of the conference authors:
No Spin Architecture
Joel's blog on architecture

Both blogs have tons of resources for aspiring architects.

There was a third presenter that raffle 4 architecture books, the raffle consisted on answering a question at light speed, doh! I'm planning on getting the books at amazon...

Overall, I got good software to try, saw that VS2008 has the split markup/code feature for web development that Macromedia had when I started doing web in 2000 and I should get a copy of Vista on my mail in the next few weeks. I'm excited about the JavaScript debugger and IntelliSense in VS2008. Hyper-V promises to be more secure than VMWare, SQL Server 2008 has the FileName type I wish I have now for my image archiving project...
I can't wait to get my hands on Virtual Earth web service and bundle it with the new maps capabilities in SQL Server 2008, if time permits, there's only 24 hours in a day and deadlines cannot be stretched :-p

Cheers!

Labels:

Wednesday, February 20, 2008

The fix for batch deletions at Publisher when use_partition_groups is set to false In Merge Replication is indeed there!!!

Yay!

The fix is in there. Please see previous post for the original bug description. We had problems when not using partition groups on our merge replication topology, whenever there were batch deletions caused by filtering those rows were deleted at the publisher during the next replication.

The faulty stored procedure was sp_MSdelsubrowsbatch


The faulty line of code, believe it or not, a single line
on the faulty sproc:

-- change tombstone type for the non-original rows (the rows that got deleted via expansion).
update dbo.MSmerge_tombstone
set type = 1
from
(select distinct tablenick, rowguid from
#notbelong where original_row <> 1) nb,
dbo.MSmerge_tombstone ts
where ts.tablenick = nb.tablenick and
ts.rowguid = nb.rowguid
option (FORCE ORDER, LOOP JOIN)

On the sproc after CU6:
update dbo.MSmerge_tombstone
set type = @METADATA_TYPE_PartialDelete
from
(select distinct tablenick, rowguid from
#notbelong where original_row <> 1) nb,
dbo.MSmerge_tombstone ts
where ts.tablenick = nb.tablenick and
ts.rowguid = nb.rowguid
option (FORCE ORDER, LOOP JOIN)


Basically the deletions caused by filtering (Partial deletes) were marked as tombstone or user deletions.

Given the following variable declarations:

declare @METADATA_TYPE_Tombstone tinyint
declare @METADATA_TYPE_PartialDelete tinyint
declare @METADATA_TYPE_SystemDelete tinyint

and assignation:

set @METADATA_TYPE_Tombstone= 1
set @METADATA_TYPE_PartialDelete= 5
set @METADATA_TYPE_SystemDelete= 6

If you ever doubted the power of a single line of code... :-p

Happy coding guys!





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Cumulative Update Number 6 for SQL Server 2005 SP2 is out!!!

Hi DBAs and Database Developers out there,
Finally the long awaited CU#6 was released on Feb 18th near mid night.

946608 Cumulative update package 6 for SQL Server 2005 Service Pack 2
http://support.microsoft.com/default.aspx?scid=kb;EN-US;946608

I'm currently testing our merge replication issues with this CU.

Even though the bug described in the DevX article is not in the KB article list, we got confirmation that the fix is on the CU#6.

So far the identity automatic management problem described on my previous post remains the same. If the user making the inserts is not a db_owner, automatic identity management ain't going to happen on your publisher...

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Thursday, February 14, 2008

Identity Range not working for Merge Replication in SQL Server 2005

Back in Sept 2007 I blogged about the problem we were having with the identity range in merge replication:@@identity not working after SQL Server 2005 upgrade The problem continued until today, this post is to explain what we figured out.

The error message that describes this problem reads as follows:

[548] The insert failed. It conflicted with an identity range check constraint in database 'DatabaseName', replicated table 'dbo.TableName', column 'ColumnNameId'. If the identity column is automatically managed by replication, update the range as follows: for the Publisher, execute sp_adjustpublisheridentityrange; for the Subscriber, run the Distribution Agent or the Merge Agent.



The identity range adjustment happens after every insert in the given article. The code responsible for the identity check adjustment is on the system trigger for the published article:
MSmerge_isn_GUID where GUID is the GUID for the given article.
...
if is_member('db_owner') = 1
begin
-- select the range values from the MSmerge_identity_range table
-- this can be hardcoded if performance is a problem
declare @range_begin numeric(38,0)
declare @range_end numeric(38,0)
declare @next_range_begin numeric(38,0)
declare @next_range_end numeric(38,0)

select @range_begin = range_begin,
@range_end = range_end,
@next_range_begin = next_range_begin,
@next_range_end = next_range_end
from dbo.MSmerge_identity_range where artid='BAEF9398-B1B1-4A68-90A4-602E3383F74A' and subid='0F9826DB-50FB-4F73-844D-AE3A111B4E1C' and is_pub_range=0

if @range_begin is not null and @range_end is not NULL and @next_range_begin is not null and @next_range_end is not NULL
begin
if IDENT_CURRENT('[dbo].[TableName]') = @range_end
begin
DBCC CHECKIDENT ('[dbo].[TableName]', RESEED, @next_range_begin) with no_infomsgs
end
else if IDENT_CURRENT('[dbo].[TableName]') >= @next_range_end
begin
exec sys.sp_MSrefresh_publisher_idrange '[dbo].[TableName]', '0F9826DB-50FB-4F73-844D-AE3A111B4E1C', 'BAEF9398-B1B1-4A68-90A4-602E3383F74A', 2, 1
if @@error<>0 or @retcode<>0
goto FAILURE
end
end
end

...


As you might have noticed already, if the insertion is made by a user that is not member of the db_owner database role, the identity adjustment won't happen. I believe this is a bug, not a feature. It forces the users that are allowed to do insertions to be owners of the database, or they will have the run out of identities error quite often and a manual adjustment will be required.

What the savvy DBA can do:

The template for all of the MSmerge_ins_GUID triggers are on the model database, these triggers are created by the system stored procedure: sp_MSaddmergetriggers_internal

If you change the code on this system stored procedure any new database creation will have the proper template for creating the merge insertion triggers. For the existing databases, you might like to modify the MSmerge_ins_GUID trigger manually, for now.


At the time I'm writing this post I'm not aware if this issue is addressed on any cumulative update. There is a similar case on the Cumulative Update released on January 15, 2008
http://support.microsoft.com/kb/941989


Happy coding guys!

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Monday, February 04, 2008

Yay!!!! The team is on TechNet Innovation Awards 2008

Hi Developer that wanders the internet searching for the solution to your bug. Take a brief moment and vote for us, bunch of developers who also wander the internet to search solutions for our bugs and blog about them to help others :)

Microsoft Canada and TechNet Innovation Code Awards


We'll be good and post more on our blog, interesting, good stuff :-p
Kidding, let the code prevail!

Oh, we're the Tablet PC team, good stuff with SQL Server 2005 and Smart Clients ;)