A Fine Slice Of SQL Server
Patrick LeBlanc eliminates a pernicious source of temptation in Power BI:
Patrick shows you how to get rid of the pie chart in Power BI Desktop. Finally a way to remove the temptation! The ability to customize the visual pane in Power BI Desktop lets you do it.
See you never, pie chart.
Comments closedSSIS error outputs are a secondary path through which the data flow can send rows that do not conform to data type, length, or transformation standards defined by the ETL developer. That’s a lengthy way to say that it’s where you can send your junk data. In the SSIS designer, clicking on a source or transformation will often show not one but two possible outputs: the primary output (the “good” data, indicated by the blue line) and the error output (identified by the red line). As shown on the flat file source below, when selecting a source or transformation, those that have an available error output will appear with both output connectors ready for selection.
Tim elaborates quite a bit on what you can do with this output.
Comments closedSebastian Sauer demonstrates using the pmap() function in purrr to call a function multiple times with different parameters:
Assume you have to call a function multiple times, but each with (possibly) different argument. Given enough repitioons, you will not want to repeat yourself.
In other words, we would like to loop over function arguments, each round in the loop giving the respective argument’value(s) to the function.
This is one of the benefits of functional-style programming: loops become higher-order functions, which take less time to write and keeps your code from looking like a pyramid of doom.
Comments closedGeorge Leopold informs us on a new project called KarelDB:
Unlike Confluent’s Kafka-based platform, KarelDB is not a streaming database. Yokota nevertheless flagged the relational database largely because it’s based on open-source components backed by Kafka. Hence, he reckons there’s a chance it could take off.
Those open source components include Calcite, an SQL framework that pushes relational queries to the data store, an approach seen as providing more efficient processing. Yokota noted that KarelDB would “automatically benefit” from upcoming Calcite optimizations.
Other open source projects such as the Apache Flink stream processing engine also have leveraged Calcite, including an SQL API. Calcite also includes an SQL parser.
Kafka already had KSQL for Kafka Streams, but this is a totally different validation of Feasel’s Law.
Comments closedEbru Ersan announces public preview 2 of the SQL Assessment API:
SQL Assessment API is a new mechanism to evaluate configuration of your SQL Server for best practices. The API methods are used by means of a SQL Server Management Object (SMO) extension and new cmdlets in SqlServer PowerShell module. API is delivered with a ruleset that is highly customizable and extensible. It can be used to assess SQL Server versions 2012 and higher, both on Windows and Linux.
Read on for instructions on how to install and what has changed since public preview 1.
Comments closedBrett Powell has a project to show Analysis Services DMVs in SQL Server Management Studio:
Just like with registered servers in SSMS, if you’re a BI administrator or developer that regularly needs to access and analyze Analysis Services models, whether that’s Power BI Premium, Azure AS, or SSAS, then quick access to the available DMVs aids your productivity.
For example you may want to quickly retrieve the DAX measures in a model including their expressions, the columns of a table, the largest columns in terms of memory consumption or cardinality, the row-level security roles and role memberships, etc. Obviously it wouldn’t be efficient to open the Power BI Desktop file or the Visual Studio solution to obtain this information and a tool like the Tabular Model Schema Reference v2.0 might be more than you need for short term and light ad hoc scenarios.
Click through for a link to Brett’s project as well as instructions on how to use it and a quick demo.
Comments closedDenzil Ribeiro shows how you can use Telegraf and Grafana to monitor Azure SQL Database databases:
SQL DB Storage
This is the dashboard for monitoring file size and space used, IO latency, and IO throughput, for each file in the database. When using Standard or General Purpose databases, which use data files in Azure blob storage, storage performance depends on several blob properties, exposed via the FILEPROPERTYEX() function.
Aside from a couple Azure SQL DB-specific steps, it’s basically the same process that Tracy Boggiano has for monitoring on-prem and IaaS SQL Server instances.
Comments closedEd Pollack has a pattern for rooting out application problems based on database activity:
We can approach I/O file stats very similarly to how we handled row counts above: Regularly collect data, store it in a reporting table, and then run analytics against it as needed. Since these database metrics are reset when SQL Server services restart, we need to collect a bit more often. We’ll also want to collect often enough to be able to correlate changes to ongoing application activity. Hourly is typically an acceptable collection frequency, but your environment may lend itself to the more frequent or less frequent collection.
What’s nice is that you can get a long way with heuristics and domain knowledge, even before applying data science techniques.
Comments closedEugene Meidinger gives us a detailed guide to Power BI performance tuning:
As a report developer, it can be frustrating a report developer, knowing that something is slow, but not being able to put your finger on it. In my mind, there are 4 main areas where there might be a slowdown:
1. Data refresh
2. Model calculations
3. Visualization rendering
4. Everything elseIdentifying which one of these is the problem is the first step to improving performance. In most cases, if a report is slow it’s an issue with step 2, your data model.
Eugene has plenty of good advice here.
Comments closedChris Webb shows off hierarchical navigation in Power Query against Azure Data Lake Storage Gen2:
While the documentation on how to import data from Azure Data Lake Gen2 Storage into Power BI is pretty detailed, the connector (which at the time of writing is in beta) that supports this functionality in the Power Query engine has some useful functionality that isn’t so obvious. If you look at the built-in documentation on the AzureStorage.DataLake M function in the Power Query Editor you’ll see there are a lot of options that aren’t in the documentation on the web yet:
Click through for an example.
Comments closed