Should we have foreign key relationship between two slowly changing dimensions?
Most of the cases we talked about are about how to build an SLC, any example of trying to have two SLCs with FK relationship in a snow flake schema?
Hi, all experts here,
Do we always have to use SCD component for the loading of data into data warehouse to handle changes of rows?
I am looking forward to hearing from you and thank you very much in advance for your help.
With best regards,
I am new to SSIS and I am investigating using the Slowly Changing Dimension transform.
The data source that I receive is a daily snapshot of the external source system table. I need to store the history of the entity attributes (Type 2 SCD) and I am using the Start / End Date mechanism.
When an entity (identified by the business key) is no longer received in the source snapshot, I would like the data flow to update the End Date of the current row to show that the entity has now expired.
Does anyone have any suggestions for a good way to achieve this ?
NB: Changing the source system extract to include and flag expired entities is not an option for me.
Many thanks
Graham
Hi, All experts here,
Thank you for your kind attention.
I have questions about Slowly Changing Dimensions. I am quite confused about when should we use type 1 ( changing), type2 (historical), or type3( fixed) for the dimensions in each table? Is there any good suggestions on that?
Thank you in advance and I am looking forward to hearing from you.
Yours sincerely,
Hi,
I would like to know if there is an easy way to load Hierarchical Dimensions with Type 2 using SSIS ( or in general).
Here is my example:
There is a Hierarchy Product Group <- Product Class <- Product. (In words, Product rolls up to Product Class and Product Class Rolls up to Product Group). Say Product Group is Type 1 and the other two are Type 2. Every night, I receive a feed for each of these tables only if the record is new or a change to an existing record.
Now, when a Product Class Record is changed to assign it to a different group then I receive the feed only for Product Class (but not for Product). To load this record, I expire the old record and create a new entry with a new Surrogate Key. Then how do I automatically cascade this change to Product and make a Type 2 change to use the new Surrogate Key from Product Class?
Any ideas would be greatly appreciated.
Thanks,
Srini
Hello,
We are having issues with SCDs that appear to be volume related. Small dimensions work fine. Pasted below is the last few lines of our package run without any contention (We get different errors at different time with contention referring to buffer or virtual memory). It seems to be calling out the SCD main task but just gives a number and not much of a description.
2) For the errors referring to a buffer ( I can paste them also but did not want to put too much at once); we have the "BufferTempStoragePath" pointing to a drive with lots of space. We have tinkered with the DefaultBufferMax Rows and Size but that seems to just control how big the "batches" are (the row count size changes you see).
Any configuration type things we could try to avoid these errors? Any more detail that can be gleaned from the messages below or the number? This is kind of a show stopper as we are late in the cycle and need larger (at this point only about 600,000 rows) volumes to go through the SCD tasks. The performance seems to be good enough (about 20 minutes). We have tens of millions working fine in fact packages not using SCDs.
Thanks. Geoff
Information: 0x4004300C at Data Flow Task, DTS.Pipeline: Execute phase is beginning.
Error: 0xC0047022 at Data Flow Task, DTS.Pipeline: The ProcessInput method on component "Slowly Changing Dimension" (45421) failed with error code 0x8007000E. The identified component returned an error from the ProcessInput method. The error is specific to the component, but the error is fatal and will cause the Data Flow task to stop running.
Error: 0xC0047021 at Data Flow Task, DTS.Pipeline: Thread "WorkThread0" has exited with error code 0x8007000E.
Error: 0xC0047039 at Data Flow Task, DTS.Pipeline: Thread "WorkThread1" received a shutdown signal and is terminating. The user requested a shutdown, or an error in another thread is causing the pipeline to shutdown.
Error: 0xC0047021 at Data Flow Task, DTS.Pipeline: Thread "WorkThread1" has exited with error code 0xC0047039.
Error: 0xC02020C4 at Data Flow Task, Control File Extended view as source [959]: The attempt to add a row to the Data Flow task buffer failed with error code 0xC0047020.
Error: 0xC0047038 at Data Flow Task, DTS.Pipeline: The PrimeOutput method on component "Control File Extended view as source" (959) returned error code 0xC02020C4. The component returned a failure code when the pipeline engine called PrimeOutput(). The meaning of the failure code is defined by the component, but the error is fatal and the pipeline stopped executing.
Error: 0xC0047021 at Data Flow Task, DTS.Pipeline: Thread "SourceThread0" has exited with error code 0xC0047038.
Information: 0x40043008 at Data Flow Task, DTS.Pipeline: Post Execute phase is beginning.
Information: 0x40043009 at Data Flow Task, DTS.Pipeline: Cleanup phase is beginning.
Information: 0x4004300B at Data Flow Task, DTS.Pipeline: "component "Insert New Rows into Product Dim" (51111)" wrote 0 rows.
Task failed: Data Flow Task
Warning: 0x80019002 at ProductDimensionIncr: The Execution method succeeded, but the number of errors raised (7) reached the maximum allowed (1); resulting in failure. This occurs when the number of errors reaches the number specified in MaximumErrorCount. Change the MaximumErrorCount or fix the errors.
SSIS package "ProductDimensionIncr.dtsx" finished: Failure.
Hi,
I am facing the problem with datatype conversions, the scenario is using derived column transformation for add additional columns and then later i am trying to impliment Slowly changing dimensions(SCM) in my job, while mapping the columns at SCM from Input to Output it gave the error like suppose if i am using the numeric(3,0) at SRC system then i converted it into single byte unsigned at derived column and it recognized at SCD but the job fail while run the package it gave the error as task can not able to conversted given data type to target system dtata type.. ifi am not given the single byte unsigned data type at dervied column at the level of SCD mapping the input to output its not accapring this mapping and return the error as can be convert from system.decimal to system.byte..
Sreenivas Amirineni
I have to load data into destination table, it has foreign key relation to two different tables called person table and organization table . sample data to be loaded is like
person_id organization_id
1Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Null
2Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â NULL
Null               1
null              null
person table and organization table doesn't have null values in them, when I try to load this data none of them are laoded, I know either person_id or organization id having null value is failing foreign key constraint. But I want to transfer all the rows except the ones having both nulls. how this can be achieved ?
Hi all,
I use the following 3 sets of sql code in SQL Server Management Studio Express (SSMSE) to import the csv data/files to 3 dbo.Tables via CREATE TABLE & BUKL INSERT operations:
-- ImportCSVprojects.sql --
USE ChemDatabase
GO
CREATE TABLE Projects
(
ProjectID int,
ProjectName nvarchar(25),
LabName nvarchar(25)
);
BULK INSERT dbo.Projects
FROM 'c:myfileProjects.csv'
WITH
(
FIELDTERMINATOR = ',',
ROWTERMINATOR = ''
)
GO
=======================================
-- ImportCSVsamples.sql --
USE ChemDatabase
GO
CREATE TABLE Samples
(
SampleID int,
SampleName nvarchar(25),
Matrix nvarchar(25),
SampleType nvarchar(25),
ChemGroup nvarchar(25),
ProjectID int
);
BULK INSERT dbo.Samples
FROM 'c:myfileSamples.csv'
WITH
(
FIELDTERMINATOR = ',',
ROWTERMINATOR = ''
)
GO
=========================================
-- ImportCSVtestResult.sql --
USE ChemDatabase
GO
CREATE TABLE TestResults
(
AnalyteID int,
AnalyteName nvarchar(25),
Result decimal(9,3),
UnitForConc nvarchar(25),
SampleID int
);
BULK INSERT dbo.TestResults
FROM 'c:myfileLabTests.csv'
WITH
(
FIELDTERMINATOR = ',',
ROWTERMINATOR = ''
)
GO
========================================
The 3 csv files were successfully imported into the ChemDatabase of my SSMSE.
2 questions to ask:
(1) How can I designate the Primary and Foreign Keys to these 3 dbo Tables?
Should I do this "designate" thing after the 3 dbo Tables are done or during the "Importing" period?
(2) How can I set up the relationships among these 3 dbo Tables?
Please help and advise.
Thanks in advance,
Scott Chang
Hello
I have a problem with setting relations properly when inserting data using adonet. Already have searched for a solutions, still not finding a mistake...
Here's the sql management studio diagram :
and here goes the code1 DataSet ds = new DataSet();
2
3 SqlDataAdapter myCommand1 = new SqlDataAdapter("select * from SurveyTemplate", myConnection);
4 SqlCommandBuilder cb = new SqlCommandBuilder(myCommand1);
5 myCommand1.FillSchema(ds, SchemaType.Source);
6 DataTable pTable = ds.Tables["Table"];
7 pTable.TableName = "SurveyTemplate";
8 myCommand1.InsertCommand = cb.GetInsertCommand();
9 myCommand1.InsertCommand.Connection = myConnection;
10
11 SqlDataAdapter myCommand2 = new SqlDataAdapter("select * from Question", myConnection);
12 cb = new SqlCommandBuilder(myCommand2);
13 myCommand2.FillSchema(ds, SchemaType.Source);
14 pTable = ds.Tables["Table"];
15 pTable.TableName = "Question";
16 myCommand2.InsertCommand = cb.GetInsertCommand();
17 myCommand2.InsertCommand.Connection = myConnection;
18
19 SqlDataAdapter myCommand3 = new SqlDataAdapter("select * from Possible_Answer", myConnection);
20 cb = new SqlCommandBuilder(myCommand3);
21 myCommand3.FillSchema(ds, SchemaType.Source);
22 pTable = ds.Tables["Table"];
23 pTable.TableName = "Possible_Answer";
24 myCommand3.InsertCommand = cb.GetInsertCommand();
25 myCommand3.InsertCommand.Connection = myConnection;
26
27 ds.Relations.Add(new DataRelation("FK_Question_SurveyTemplate", ds.Tables["SurveyTemplate"].Columns["id"], ds.Tables["Question"].Columns["surveyTemplateID"]));
28 ds.Relations.Add(new DataRelation("FK_Possible_Answer_Question", ds.Tables["Question"].Columns["id"], ds.Tables["Possible_Answer"].Columns["questionID"]));
29
30 DataRow dr = ds.Tables["SurveyTemplate"].NewRow();
31 dr["name"] = o[0];
32 dr["description"] = o[1];
33 dr["active"] = 1;
34 ds.Tables["SurveyTemplate"].Rows.Add(dr);
35
36 DataRow dr1 = ds.Tables["Question"].NewRow();
37 dr1["questionIndex"] = 1;
38 dr1["questionContent"] = "q1";
39 dr1.SetParentRow(dr);
40 ds.Tables["Question"].Rows.Add(dr1);
41
42 DataRow dr2 = ds.Tables["Possible_Answer"].NewRow();
43 dr2["answerIndex"] = 1;
44 dr2["answerContent"] = "a11";
45 dr2.SetParentRow(dr1);
46 ds.Tables["Possible_Answer"].Rows.Add(dr2);
47
48 dr1 = ds.Tables["Question"].NewRow();
49 dr1["questionIndex"] = 2;
50 dr1["questionContent"] = "q2";
51 dr1.SetParentRow(dr);
52 ds.Tables["Question"].Rows.Add(dr1);
53
54 dr2 = ds.Tables["Possible_Answer"].NewRow();
55 dr2["answerIndex"] = 1;
56 dr2["answerContent"] = "a21";
57 dr2.SetParentRow(dr1);
58 ds.Tables["Possible_Answer"].Rows.Add(dr2);
59
60 dr2 = ds.Tables["Possible_Answer"].NewRow();
61 dr2["answerIndex"] = 2;
62 dr2["answerContent"] = "a22";
63 dr2.SetParentRow(dr1);
64 ds.Tables["Possible_Answer"].Rows.Add(dr2);
65
66 myCommand1.Update(ds,"SurveyTemplate");
67 myCommand2.Update(ds, "Question");
68 myCommand3.Update(ds, "Possible_Answer");
69 ds.AcceptChanges();
70
and that causes (at line 67):"The INSERT statement conflicted with the FOREIGN KEY constraint
"FK_Question_SurveyTemplate". The conflict occurred in database
"ankietyzacja", table "dbo.SurveyTemplate", column
'id'.
The statement has been terminated.
at System.Data.Common.DbDataAdapter.UpdatedRowStatusErrors(RowUpdatedEventArgs rowUpdatedEvent, BatchCommandInfo[] batchCommands, Int32 commandCount)
at System.Data.Common.DbDataAdapter.UpdatedRowStatus(RowUpdatedEventArgs rowUpdatedEvent, BatchCommandInfo[] batchCommands, Int32 commandCount)
at System.Data.Common.DbDataAdapter.Update(DataRow[] dataRows, DataTableMapping tableMapping)
at System.Data.Common.DbDataAdapter.UpdateFromDataTable(DataTable dataTable, DataTableMapping tableMapping)
at System.Data.Common.DbDataAdapter.Update(DataSet dataSet, String srcTable)
at AnkietyzacjaWebService.Service1.createSurveyTemplate(Object[] o) in J:\PL\PAI\AnkietyzacjaWebService\AnkietyzacjaWebServicece\Service1.asmx.cs:line 397"
Could You please tell me what am I missing here ?
Thanks a lot.
I have one question regarding Slowly Changing Dimension component in SSIS. Does SCD also delete records in warehouse if they does not exist in source anymore, or does SCD only insert new and update existing records? Can someone explain me a little bit more about inferred members? Thanks.
View 1 Replies View RelatedI have a Type I SCD situation, ie, insert if new (by checking the business ID) and update if any attributes for a given business ID has changed.
The way I usually do this, (and I believe this is how most people do it), is I use a LOOKUP TASK to determine if the business ID exsist in the target table. If it doesn't then I insert. If the business ID exists, then I bring back the associated attributes and use a CONDITIONAL SPLIT TASK to compare if any of the incoming attributes are different. If there are changes, then update.
In doing this comparision, I often run into situations where I end up comparing a NULL value to something, which does not result in FALSE, but a NULL result. To get around this, I first check for NULLs and convert them into something valid before I do the comparision, but this results in a messy comparison expression, especially if I have to compare a lot of attributes.
So, how do you guys handle this?
As an alternative, I am looking into the SLOWLY CHANGING DIMENSION TASK, which I also have some questions on, but I would like to first address the above. Thank you.
I have a package using Slowly changing dimension in the data flow task. It works fine if the number of records are less but for a large file the package fails with the "Violation of Primar Key" error even though there are no duplicate records in the table.
for eg i have a table with employee database with a composite primary key comprsing of Name and Employee Id. I need to do an UPSERT depending on the Name and Employee Id combination. I have a file with 100,000 records and when i try to execute the package it gives an error 'cannot insert duplicate data' even though the combination does not exist in the database.
Please help.
Aashna Behl
Hi,
We have been using tasks generated from the SCD wizard. We have smaller dimensions (< 30,000 rows) that work well. Our Product Dimension package is giving us performance problems (taking 7 hours to do 600,000 rows when 80,000 records are updated; the rest new inserts). It is similar to the smaller dimensions. Several columns are type 1 and are doing update statements; several are type 2 doing updates and inserts. The package had a complicated view as the initial task, but we have since modified to use a SQL command with variable and now the initial read appears quick, but is chunking in 10,000 record increments and taking the 7 hours (never let finish previously). So the package is pretty basic now (reading a source, a small derive and data conversion, a small lookup (cached 30,000 records) for a description, then the SCD). Before I start replacing what the SCD generates with stored procedures, anyone have any suggestions as to what might be the issue? We believe we have increased the number of type 2 columns and the SCD definately has more to do than just an insert or update, but 7 hours for 600,000 records seems excessive. Interestingly, the source task never turns green. Previously when we had a Merge Join it completed the read and bottlenecked at a sort and a Merge Join. Now that has been removed and simplified, and all tasks remain yellow with the 10,000 (actually 9,990 I think) chunks appearing at the source, then the SCD before the next chunk appears to be read. On the general release (not the beta). Thanks in advance!
i am using SCD to insert or update .my source and destination table are Oracle and i am using Orcale OLEDB provider . i am getting the following error while executing the package.what could be the solution
[Slowly Changing Dimension [58]] Error: An OLE DB error has occurred. Error code: 0x80040E5D. An OLE DB record is available. Source: "Microsoft OLE DB Provider for Oracle" Hresult: 0x80040E5D Description: "Parameter name is unrecognized.".
Thanks
Jegan
Hi There,
Just wondering if any of you implemented a (Kimball type 2) dimension structure, in which a ParentID column exists which points to a record from the same dimension table, using a SCD objects in SSIS. The ParentID column would have to be "Historical".
The challange here is that you would need to go through the table twice somehow, because if I would do a lookup of the parent record in the first run, I wouldn't be sure if I got the right parent record.
Thnx, Jeroen.
I have a Company Dimension table that consists of various sources. One source will provide me address information, another source will provide industry info, etc. I created a historical load package that will pull all of this together so that I have all the necessary data related to a company in one record. All is well.
Since my company data is coming from various sources, how can I tell the SCD to update certain fields but not others for a type 2 change. In essence, I would like to "pull forward" the data that was in the original database row and then update it with only the changes coming from the proper source data. For example, if an address changed I will get the new address from the source but will not have the industry info. I would like to create the new record with the new address but also keep the industry data in tact. Is this possible?
Currently I will get the new record with the new address but will have null values for the industry data.
Thanks
I am trying to move data from a transactional database to a data warehouse using a slowly changing dimension. The transactional data comes from a view in SQL server that takes <60 seconds to run and returns about 60k rows. The warehouse table is currently 80k rows long (and growing), and contains 7 historical (type 2) dimensions. When I execute the package in BIDS the DataFlow Task begins to execute, and shows that between 20k and 30k rows have been pulled from the data source into the SCD Transform in the first hour before it simply stops doing anything. This is not to say execution stops; it continues. There is no error thrown. No warning given. System resources are 98% free. The database is not being hit at all. And yet, I have let the package sit 'still' as it were for over 8 hours, and nothing ever happens.
Here is a copy of one log:
starttime endtime message
4/8/2008 9:36 4/8/2008 9:36 Execute phase is beginning.
4/8/2008 9:36 4/8/2008 9:36 PrimeOutput will be called on a component. : 1715 : Union All
4/8/2008 9:36 4/8/2008 9:36 A component has returned from its PrimeOutput call. : 1715 : Union All
4/8/2008 9:36 4/8/2008 9:36 PrimeOutput will be called on a component. : 2912 : Staged Queues
4/8/2008 9:36 4/8/2008 9:36 Rows were provided to a data flow component as input. : : 2970 : DataReader Output : 70 : Slowly Changing Dimension : 81 : Slowly Changing Dimension Input : 9947
4/8/2008 9:37 4/8/2008 9:37 A component has returned from its PrimeOutput call. : 2912 : Staged Queues
4/8/2008 9:37 4/8/2008 9:37 A component has returned from its PrimeOutput call. : 2912 : Staged Queues
4/8/2008 9:59 4/8/2008 9:59 Rows were provided to a data flow component as input. : : 1718 : New Output : 1715 : Union All : 1716 : Union All Input 1 : 3825
4/8/2008 9:59 4/8/2008 9:59 Rows were provided to a data flow component as input. : : 1688 : Historical Attribute Inserts Output : 1682 : Get End Date : 1683 : Derived Column Input : 645
4/8/2008 9:59 4/8/2008 9:59 Rows were provided to a data flow component as input. : : 1702 : Derived Column Output : 1692 : Update End Date : 1697 : OLE DB Command Input : 645
4/8/2008 10:01 4/8/2008 10:01 Rows were provided to a data flow component as input. : : 1759 : OLE DB Command Output : 1715 : Union All : 1758 : Union All Input 2 : 645
4/8/2008 10:01 4/8/2008 10:01 Rows were provided to a data flow component as input. : : 2970 : DataReader Output : 70 : Slowly Changing Dimension : 81 : Slowly Changing Dimension Input : 9947
4/8/2008 10:24 4/8/2008 10:24 Rows were provided to a data flow component as input. : : 1718 : New Output : 1715 : Union All : 1716 : Union All Input 1 : 3859
4/8/2008 10:24 4/8/2008 10:24 Rows were provided to a data flow component as input. : : 1688 : Historical Attribute Inserts Output : 1682 : Get End Date : 1683 : Derived Column Input : 641
4/8/2008 10:24 4/8/2008 10:24 Rows were provided to a data flow component as input. : : 1702 : Derived Column Output : 1692 : Update End Date : 1697 : OLE DB Command Input : 641
4/8/2008 10:26 4/8/2008 10:26 Rows were provided to a data flow component as input. : : 1759 : OLE DB Command Output : 1715 : Union All : 1758 : Union All Input 2 : 641
4/8/2008 10:26 4/8/2008 10:26 Rows were provided to a data flow component as input. : : 2970 : DataReader Output : 70 : Slowly Changing Dimension : 81 : Slowly Changing Dimension Input : 9947
4/8/2008 10:49 4/8/2008 10:49 Rows were provided to a data flow component as input. : : 1718 : New Output : 1715 : Union All : 1716 : Union All Input 1 : 3969
4/8/2008 10:49 4/8/2008 10:49 Rows were provided to a data flow component as input. : : 1688 : Historical Attribute Inserts Output : 1682 : Get End Date : 1683 : Derived Column Input : 662
4/8/2008 10:49 4/8/2008 10:49 Rows were provided to a data flow component as input. : : 1702 : Derived Column Output : 1692 : Update End Date : 1697 : OLE DB Command Input : 662
4/8/2008 10:49 4/8/2008 10:49 Rows were provided to a data flow component as input. : : 1793 : Union All Output 1 : 1787 : Get Start Date : 1788 : Derived Column Input : 9947
4/8/2008 10:49 4/8/2008 10:49 Rows were provided to a data flow component as input. : : 1814 : Derived Column Output : 1797 : Insert Destination : 1810 : OLE DB Destination Input : 9947
4/8/2008 15:34 4/8/2008 15:34 The pipeline received a request to cancel and is shutting down.
4/8/2008 15:34 4/8/2008 15:34 Thread "WorkThread1" received a shutdown signal and is terminating. The user requested a shutdown or an error in another thread is causing the pipeline to shutdown.
4/8/2008 15:34 4/8/2008 15:34 Thread "WorkThread1" received a shutdown signal and is terminating. The user requested a shutdown or an error in another thread is causing the pipeline to shutdown.
4/8/2008 15:34 4/8/2008 15:34 The pipeline received a request to cancel and is shutting down.
4/8/2008 15:34 4/8/2008 15:34 Thread "WorkThread1" has exited with error code 0xC0047039.
4/8/2008 15:34 4/8/2008 15:34 Thread "WorkThread1" has exited with error code 0xC0047039.
Notice the time difference between the last OnPipelineRowsSent event and the first OnError event (when I clicked the stop button): 5 hours! In all that time, SSIS did not log a single event, or use more than 2% of my processor or exceed 1GB page file or hit the database even once! I am assuming this means it is simply not doing anything. It is not failing, nor is it executing, it is just sitting there.
Has anyone experienced a similar problem? Does anyone know how I might troubleshoot this? Thanks in advance for any help, and let me know if I need to clarify. Also, I am new to SSIS, so if I am missing something obvious, go easy on me! Thanks.
Mitch Connors
The warehouse I am writing packages for has sort of a "Type 1.5" design for most of its DIMs that I am trying to get to work with the slowly changing dimension object.
Basically it should behave like a type 1 with updates in place BUT send the old prior rows/values to an "archive" server to hold the historical data. Unlike a Type 2 this data will not be used for any processes - but it needs to be kept for historical reseach and auditing.
Any ideas to easily do with the SCD wizard? I thought using the wizard as a type 1 and then after the wizard is done attaching the "Historical Attribute Inserts Output" to the archive db/table would do the trick but that output from the SCD object never has data. I could manually do it with a lookup and so forth but I thought I'd check in here first to see if I am just overlooking something with the SCD object.
Is there a way to change the data source for a SCD Component without having to go back to reinsert the matches for Source and Destination columns. Note the underlying data table hasn't changed, just the server the table resides on. Whenever I change the data source I am noticing that I have to painfully go back and match columns one by one.
Thanks
David
Hi.
View 9 Replies View RelatedHi
How does a SCD work?
e.g
does it build has values for inbound value and compare it to a stored hash value to determine if a change exists?
Are each of the attributes chequed one by one for a change?
Does a lookup occur at somepoint on the target table. i.e If I have a 16m row table will it lookup and cache all 16m rows or is it smart enough to only lookup and cache the rows that it expects based on a PK value
Basically what I'm asking is for a technical explanation as to how it works and how to tune it or the underlying data to make it perform well.
Thanks for your help
Marcus
Hi,
I have a problem with the SCD-transformation in SSIS. I have a variable that holds the batchid for the current batch and I want to add this variable to the datapipline in the Data Flow Task.
This is done by using a Derived Column, so far so good. The problem occurs in the Slowly Changing Dimension transformation where I do som evaluations of changed columns BUT I don´t want to do any evaluation of the batchid-variable because then all historical batchid will be updated.
I only want to update the batchid for row that have changed in the current batch.
Is it possible to do this in any way without adding the Derived Column after the SCD transformation??
Thank for any help!!
Patrick
We're using slowly changing dimensions to control a number of data tables in our system. Each table has five or six business keys, but the indexes of the tables are built so they're as efficient as possible (i.e. the fields with the highest diversity are listed first). How does the SCD wizard determine the order of the business key fields? Is there a way I can view or manipulate the statement the SCD task is using to make sure either (a) the indexes match the statement, or (b) the statement matches the indexes?
View 1 Replies View Related
On the face of it, the Slowly Changing Wizard seems a great idea, but is it really any good in the longer term? After you have selected your Type 1 and/or Type 2 changing columns ... then you have "customised" the generated data flow and carefully saved it ... how do you change the column definitions in the future?
If I want to add another column and make it Type 2 how do I go about it? If I run the "Wizard" doesn't this just destroy all my previous customisation work?
I have tried looking in the .dtsx xml file ... hmmm. I notice it's not really editable without some inside information. All those magic numbers in there ... I've fallen foul of them in the past with cut/paste or trying to INSERT a data flow task on the IDE ... luckily I back up my projects on a regular basis. I now have quite a large collection of Projects with the suffix "_corrupt". Are things going to get better?
Hasta SP2, eh?
I have a SSIS package which contains a number of slowly changing dimension transformations. While the majority work I have one which gives me the following error 'Error: The variable "System::LocaleID" is already on the read list. A variable may only be added once to either the read lock list or the write lock list. '. This error only occurs if the destination table holds data. If I truncate the table and reload the data then the package complete successful. The only difference I can see between this dimension transformation and the other dimension transforms is that the one in question has 2 business keys while the rest have 1.
Can anyone shed light on this?
Thanks
Hi,
We're currently running into an interesting situation where it seems that a Slowly Changing Dimension Transformation believes that 'Å“' (ASCII #156) is the same as 'oe' (ASCII #111 + ASCII #101).
To make a long story short, one of our integration package updates some Product table based on the result of a Slowly Changing Dimension Transformation with three outputs: Unchanged, New and Changing Attribute Updates. Among the columns leading to a row redirection in the Changing Attribute Updates output is some French Description column defined in SQL Server as a varchar(60) (external column) and in the SSIS package as a (DT_STR, 60, 1252) (input column). Now, when the SCD Transformation compares the word 'coeur' (external column) with the word 'cœur' (input column) in this French Description column for a given row, the row is redirected to the Unchanged output (no other columns changed...) instead of to the Changing Attribute Updates output.
Is my example clear enough? Any idea what could explain this unfortunate result? Note that from a strict French point of view, 'Å“' instead of 'oe' is a typographical fantasy and that in my example above, the word 'coeur' ("heart") is really spelled 'c' + 'o' + 'e' + 'u' + 'r', but we're talking programmed comparison here, not linguistic, right?
Any comment will be appreciated.
Thanks,
AL
In our application we have created a SSIS package which extracts data from staging table and places the same in destination table. We have created a slowly changing dimension for the same. Slowly changing dimension uses a composite business key of two columns to decide whether it is a old record or a new record.
Problem : On execution of the package it copies duplicate records with same business keys instead of updating the same. Also the same does not happen for all records. For few records update works fine but for others it inserts a new duplicate record.
I will appreciate if anybody can guide me where I am doing something wrong.
Thank you
Hello
I use SSIS to load a Unicode file into a single table
I Use a "slowly changing dimension" task to load the destination table and when i map a column (DT_WSTR) to a column with the datatype nvarchar(max) i have an error message that say that i can't map theses columns because there have not the same datatype.
I find a workaround : i map all my cols except the colums that must fill the cols with datatype nvarchar(max) , and after i modify manually the 2 subtask generated by the "slowly changing dimension" task (the insert and the update) and with this way i don't have error messages
It works fine but is it the good way?
It seems to be a bug from ssis?
Thanks in advance.
Nicolas Lievain
I have as simple IS package with a Flat File input and SCD Transform. The package is being used to load a Dimension Table, obviously.
The Table was designed in Analyical Services using the Dimension Wizard which very nicely adds End Date, Start Date, Status and Original ID to the Dimension Table design. I then Generate Relational Scheme... and Viola there is a Dim Table in my data warehouse database!
I next attempt to use the IS package with SCD Transform to load said Dim Table. The SCD Transform Wizard does a nice job of using the End and Start dates and Status fields in my new Dim Table, but I can not find any way to use the Original ID field?
I guess I was expecting that since the SCD Transform Wizard 'knows' how to use all the other fields in this Dim table why not the Original ID field? I know what the Original ID field is for - that's not the issue. I just can not figure out how to 'make' my new IS Data Flow with said SCD Transform use the Original ID field ?
Anyone ?
Hi,
I think slowly changing dimension object is not a good choice to update my dimension. It's running slower than I expected. my dimension records has surrogate keys from a control table that SCD is looking up whenever it encounters a new record.
Any alternative I can use?
I have an existing SSIS that uses SCD on a rather large table. I am also migrating to SQL2014 Enterprise. My question is, is it possible to use SCD and Columnstore(CS) together? I know that I can drop the CS and add a business key then insert data. Then drop the business key and add the CS back.
View 2 Replies View RelatedWe have successfully built a SSIS ETL implementation for a data mart. Most of our dimension loads are using the slowly changing dimensions task. We successfully built every package and had 1 complete successful load.
We have made a modification to one of the tables that now has 16 mil records in it. I open the dimension's package and it takes 30 sec - 1 minute to validate. When I go to the Data Flow tab and attempt to open the Slowly Changing Dimension task, SSIS will freeze up. I will get no response for hours. I my testing so far SSIS has yet to come back.
My CPU usage is below 5%. devenv.exe memory usage is at 113 Mb. My computer is using 400mb / 1Gb of memory. The status bar at the bottom says "ready". I have let it sit for up to 2 hours with no results. When I kill the process in the Windows Task Manager it ends instantly.
I have also tried deleting the task and adding a new Slowly Changing Dimension Task. When I select the table from the drop down I get the same results. I have noticed this with all my million + record tables that use the slowly changing dimension task but not the smaller tables.
I am also seeing the problem when I am in "Work Ofline" mode.
I am accessing a SQL 2005 server over a VPN connection. I am connecting to the server using a Native OLE DB OLE DB for SQL Server connection. My computer is running Windows 2000 SP4, Intel Pentium M1.86 Ghz, 1 Gb of RAM.
Can a Slowly Changing Dimension Task be used on large tables? I can understand the process taking a while to run but I do not understand why I can not edit the task.