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Day: December 1, 2021

Updates in Azure Synapse Analytics

Published 2021-12-01 by Kevin Feasel

Saveen Reddy shows how the Synapse product team has been busy this year:

Previously, Synapse workspaces had a kind of database called a Spark Database. Spark databases had two key characteristics:

– Tables in Spark databases kept their underlying data in Azure Storage accounts (i.e. data lakes)

– Tables in Spark databases could be queried by both Spark pools and by serverless SQL pools.

To help make it clear that these databases are supported by both Spark and SQL and to clarify their relationship to data lakes, we have renamed Spark databases to Lake databases. Lake databases work just like Spark databases did before. They just have a new name.

Okay, this is the kind of change I can do without. That’s a really dumb name. Spark databases tell you what a thing is. It’s a database which lives in Apache Spark. Lake databases run what? Apache Spark. But if anything really should be called a Lake database, it’d be a serverless SQL pool’s database because everything in there is built on top of the data lake—it’s all external tables pointing to a lake. So calling a Spark database a Lake database brings more confusion than elucidation.

Most of the other changes on that list? Really cool. This one? Not at all.

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Variables and Scope in Powershell

Published 2021-12-01 by Kevin Feasel

Dave Mason continues a quest into the bowels of Powershell:

Let’s talk a little bit about PowerShell variables and how long they exist within the scopes they’re defined. I’ve encountered some behavior that for me, was unexpected. It’s made my development efforts unproductive–especially when it comes to debugging.

Just like with notebooks, it’s important to remember that the Powershell prompt has a session, and that you aren’t running fresh every time. You can also use Dave’s solution to the problem, which makes sense as well.

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Using the Fail Activity in Azure Data Factory

Published 2021-12-01 by Kevin Feasel

Rayis Imayev thinks about failure:

Recently, Microsoft introduced a new Fail activity (https://docs.microsoft.com/en-us/azure/data-factory/control-flow-fail-activity) in the Azure Data Factory (ADF) and I wondered about a reason to fail a pipeline in ADF when my internal being tries very hard to make the pipelines successful once and for all. Yes, I understand a documented explanation that this activity can help to “customize both its error message and error code”, but why?

Click through for Rayis’s take. I’ll just be here cracking jokes about how Fail activities are banned in my code because I expect it to have a positive outlook on life.

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A Heap of Pain

Published 2021-12-01 by Kevin Feasel

Chad Callihan explains the dislike for heaps in SQL Server:

A table is considered a heap when it is created without a clustered index. Data isn’t in any type of ordered state. Some data is over here, some data is over there.

When you are inserting data into a heap, that data is tossed in wherever. Think of it like your junk drawer. It’s not organized into its own little sections. What do you do when you have something to add such as a pair of scissors or an old pen? You open the drawer, toss it in, and close it up without giving it a second thought.

Like Chad mentions, there are uses for heaps. And when you move to Azure Synapse Analytics, there are more uses for heaps. But with on-premises SQL Server, a heap is usually a mistake.

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