Author: Linxiao Ma

DAX – Ranking with Hierarchy Drill-Down

Problem We can use the DAX RANKX function to return the rank of an item based on one of its numerical attribute. For example, we can create a measure using RANKX function to calculate the ranks of the product categories based on the order quantity within the product categories. This measure will normally work fine … Continue reading DAX – Ranking with Hierarchy Drill-Down →

DAX – Dynamically Showing Title by Slicer in Power BI

When building a Power BI report page for analysing data by a specific dimension (e.g., customer, product and category), we often need to dynamically show the title of currently selected item(s). One trick to show the title based on the current filter context is to use Multi-Row Card visual (we can also use the single … Continue reading DAX – Dynamically Showing Title by Slicer in Power BI →

Power Query – Parameterised Files Loading from a Year-Month-Day folder Hierarchy

In one of my previous blog post, I described an approach to load text files from Azure Data Lake Store to Power BI filtered by the date period specified by users through setting the period start and period end parameters. That approach is capable to load text files located at the same folder. However, there … Continue reading Power Query – Parameterised Files Loading from a Year-Month-Day folder Hierarchy →

Anomaly Detection with Azure Stream Analytics

Anomaly detection is a very common use case in IoT related deployments. A new ANOMALYDETECTION operator has been recently added into Azure Stream Analytics and is currently at public preview. ANOMALYDETECTION operator detects anomalies based on Exchangeability Martingales (EM) that supports online test of the exchangeability of a sequence of event values. When the distribution of the sequence … Continue reading Anomaly Detection with Azure Stream Analytics →

Power Query – Extract Multiple Tags Stored in a Single Text Field

Problem It is not rare to see that multiple attributes are stored in a single text field especially for tagging enabled applications where an unfixed number of tags may associated with an article or post. Those tags are often stored in a single text filed with a delimiter to separate them. When reporting, we often … Continue reading Power Query – Extract Multiple Tags Stored in a Single Text Field →

Power Query – Parameterised Files Loading from Azure Data Lake Store within a Given Date Range

Power BI now supports data load from Azure Data Lake Store. We can connect to a folder in the Azure Data Lake Store and load all files from that folder. However, we often don't want to or aren't able to load all the files in the Azure Data Lake Store folder into Power BI due to … Continue reading Power Query – Parameterised Files Loading from Azure Data Lake Store within a Given Date Range →

SSIS in Azure #1 – Periodically Ingesting Data from SQL Database into Azure Data Lake using SSIS

*The source code created for this blog post is located here. The low cost, schema-less and large column attributes of Azure Data Lake Store along with the large number of supported analytic engines (e.g., Azure Data Lake Analytics, Hive and Spark) makes it a prefect store-everything repository for enterprise data. We can offline the copies of business … Continue reading SSIS in Azure #1 – Periodically Ingesting Data from SQL Database into Azure Data Lake using SSIS →

Scaffolding Azure Machine Learning Experiments

*please download the source code here Microsoft has released the public preview of their newest data science service, Azure Machine Learning, that contains a collection of components to support the end-to-end machine learning solution. The Azure Machine Learning Workbench and the Azure Machine Learning Experimentation service are the two main components offered to machine learning practitioners … Continue reading Scaffolding Azure Machine Learning Experiments →

Azure Stream Analytics Patterns & Implementations

Thanks to the increased popularity of IoT and social networks, steaming analytics has become a hot topic and attracted more and more attentions in the data analytics community. Many people (e.g., this and this) believe streaming analytics is the future that will take over the use cases that are traditionally targeted by batch-oriented analytics. Azure … Continue reading Azure Stream Analytics Patterns & Implementations →