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lherbert501's avatar
lherbert501
Post Prodigy
2 years ago
Solved

ETL Data flow multiple servers

Hi,   I currently have a stored procedure as my etl process and it inserts data into two tables in SSMS.   It currently uses synonyms in SSMS using multiple servers,tables and joins.   My quest...
Dataflows
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  • frithjof_v's avatar
    frithjof_v
    2 years ago

    To be honest, Fabric is new to me as well. And I have more of a Power BI background, so I know Power Query quite well, but I don't have so much real experience about SQL database, stored procedure, data warehouse admin, etc.

     

    I have tested a lot of features in Fabric, but I haven't used them in production (I have only used Power BI in production).

     

    If I understand correctly, you want to build an analytical data store in Fabric (either as a Fabric Lakehouse or Fabric Warehouse). 

     

    I guess you have some operational systems which are your ultimate data sources. I think a common pattern is

     

    Data source -> Pipeline (with or without a custom SQL query) -> Staging files or tables (Bronze Lakehouse) -> Notebook (ETL, upsert, etc.) -> Tables (Silver Lakehouse) -> Notebook (ETL, upsert, etc.) -> Tables (Gold Lakehouse)

     

    or

     

    Data source -> Pipeline (with or without a custom SQL query) -> Staging tables (Warehouse) -> Stored procedure (ETL, upsert, etc.) -> Gold Tables (Warehouse)

     

    I think also Lakehouse (Bronze) -> Lakehouse (Silver) -> Warehouse (Gold) is a normal pattern. Here you will probably find a lot of information if you Google "Medallion architecture in Fabric".

    But I think this is up to your organization to decide if you want to go all in on Lakehouse, Warehouse or a mix.

     

    Fabric Lakehouse uses Spark language (you can choose between and mix PySpark, SparkSQL, Scala or SparkR).

     

    Fabric Warehouse uses T-SQL language (but there are some limitations, because the underlying storage format is Delta Lake so not all T-SQL commands are available). I suppose you can Google to search for which workarounds people are using to adapt to the language limitations.

     

    A general advice is to use the tools which work well with your current skillset (also bearing in mind which direction you want to go).

    Using the Fabric Trial, you can test Fabric and its tools cost-free for a period.

     

    So I don't think using Dataflows Gen2 is a must. Actually, my impression is that it is quite heavy on resource-consumption. My impression is that it is a tool for low-code, UI-based ETL (which I like, coming from a Power BI background).

     

    Hopefully someone with more practical experience than me can guide you further.

     

    I think this is a great blog (serverlesssql.com) by AndyDDC.

    He can probably correct any mistakes I made in the text above here 😁  

     

    I also like this blog: Fabric: Lakehouse or Data Warehouse? - Sam Debruyn

    Although I don't think it's necessary to use both Lakehouse and Data Warehouse. It's just an option.  

frithjof_v's avatar
frithjof_v
Community Champion
2 years ago

I'm not entirely sure what synonyms in SSMS / SQL are.

 

Are the server and table names dynamic? If yes, could you explain a bit more about how they are dynamic?

Or are they static (do not change)?

 

Joins can be done in Power Query M, and they can (in some circumstances) fold back to the source. Easiest way to check it, is by connecting to each source table in Power Query M, and then join the tables in Power Query M, and then check if query folding is taking place (either by looking for the query folding indicator in Power Query, or check the query logs in your source system).

 

Are you planning to use purely Power Query M in the Dataflow Gen2, or are you planning to write a native SQL query as the first step in Power Query?

 

Query folding on native queries - Power Query | Microsoft Learn

lherbert501's avatar
lherbert501
Post Prodigy
2 years ago

Hi frithjof_v 

 

Thankyou so much for getting back to me.

 

So a Synonym is just essentially an alias for a database object. They can change a lot with what I deal with e.g. pointing it to test and dev environments with the same fields.

 

If e.g. you were joining to the destination table that you are inserting into (snapshot table) to check if the id exists or not, could this be done in power query?

 

I'm open to using both, but as we have quite an old fashioned current method of bulk stored procedures inserting for our ETL, I didn't know if it was better to change the whole thing to Dataflow Gen2, or still use the whole existing code in SSMS just into Power Query. 

 

I thought the latter defeated the object of migrating our data warehouse but I'm not sure.

 

Thanks

 

Liam