Migrating from Azure SQL Database to Data Warehouse

1
votes

I currently have an Azure SQL database, where the data in it is all in a star schema (Fact/Dim tables with column store indexes) and is used exlusively for a reporting app. We currently use a Premium database instance with 250 DTUs and it is about 150GB in size, but increasing all the time.

For a similar price I could create an SQL Data Warehouse instance with 100 DWUs. My concern is that as it is only 100 DWUs vs 250 DTUs, that I would actually see a performance reduction.

I know that DWUs and DTUs are not directly comparable, but can anyone tell me if I am likely to see a performance boost/reduction in these circumstances?

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azure-sql-databaseazure-sqldw

1 Answers

1
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For what it's worth, 1 DWU = 7.5 DTU with respect to server capacity as explained here.

When you look at the server instance that you provision a DW instance on:

  • 100 DWU instance consumes 750 DTUs of server capacity. This means you receive 500 DTUs more than the 250 DTUs associated with the Azure SQL Database Premium tier you currently have.
  • 400 DWU instance consumes 3,000 DTUs of server capacity

Take in consideration you have lesser concurrency with Azure SQL Data Warehouse.