capture delta

how can I capture delta in SQL Server 2005 to refresh base tables in a data warehouse?What is "delta"? Changes?

Is this a SQL Server question or an SSIS question?|||yes delta are changes. I think its a SSIS question and also a SQL Server question.|||Well, you'll have to stage your data from run to run and then compare changes from your staged table and your source table using a variety of SSIS tasks.

Or, you have an update flag in your source table that is set to yes everytime the data is updated/inserted. Then in SSIS, you can just pull those records where the update flag is set to yes.

There are several ways to accomplish what you desire.|||

Ideally you will write your extract query to only return changed rows. This depends on having some date for similar indicator columns in the source that would indicate if a row has changed, and therefore should be included in the query result.

If this is not possible, then you need to extract all data and compare for any changes. The SCD Transform (Wizard) can help you build a package that does this.

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what is SCD transform wizard? Is there any document on this?

also is there no way to find out which dml's were executed against a specific object? is it not possible to extract these dml's from transaction log?

|||Please read through the documentation that comes with SSIS and online: http://msdn2.microsoft.com/en-us/library/ms141026.aspx

SCD is "Slowly Changing Dimension"|||

When you install SQL Server, by default it will also install SQL Server Books Online, the product documentation. Try looking "SCD" up in the index, it has an entry "SCD transformation". This will take you to the "Slowly Changing Dimension Transformation" topic. Here is the online link as well- http://msdn2.microsoft.com/en-us/library/f8849151-c171-4725-bd25-f2c33a40f4fe(SQL.90).aspx

There are products out there that can read a transaction log, Apex SQL, Red-Gate, Lumigent all have them, but I think they are all interactive tools, rather than a way of capturing and replaying the statements. You could use SQL Trace (Profiler) to capture the statements, but obviously this is not retrospective.

If you want to replay the exact same statements on another server and/or DB, then look at transactional replication. This uses a log reader agent under the covers.

You said you had a DW, and what I assumed was an OLTP source DB. I would not expect the DW to have the same structures as the OLTP, so this log method is not really an option.

|||well we are infact replicating that table. Does transactional replication mean that you can capture/replicate only the DML(insert,update,delete) for specific objects. Since its a Data store on the other end the structure of the receiving table would be same as the source.