Building The Data Warehouse-less Data Warehouse (Part 2 of 2)

/ Mike / 1 Comment

Part 1 of this series can be found here.

In my previous post I discussed and explored the feasibility of building a simplified reporting platform in Microsoft Azure that did away with the need for a relational data warehouse. In this article, I proposed that we land, process and present curated datasets (both dimensional files for our data warehouse “layer” and other data assets for our data scientists to work with) within Azure Data Lake Store, with the final step being to product a series of dimension and fact files to be consumed by our semantic layer. The diagram below highlights this approach:

conceptualmodeldwlessdw

At the end of the previous post I’d produced our data warehouse files (dimensions and facts) and in this second and final part I will show how we consume these files with our semantic layer (Azure Analysis Services) to finally present a business-friendly reporting layer without a data warehouse in size.

Semantic Layer

A semantic layer presents the business view of the data model, and allows users to interact with the layer without needing knowledge of the underlying schema or even knowledge of writing SQL code. In the words of my colleague Christian Wade, it’s “clicky-clicky draggy droppy” reporting that provides a single version of the truth without risk of users creating inaccurate measures by a misplaced join or incorrect Group By statement.

Microsoft’s semantic layer offering is Azure Analysis Services, and allows users to connect to models built with Analysis Services using any compliant tool, such as Power BI and Tableau.

I create an Azure Analysis Services project in Visual Studio, and connect to my Azure Data Lake Store from Part 1 (Ensure you change your model to use the latest SQL Server 2017/Azure Analysis Services Compatibility Level) :

aasdatalakestore

Azure Analysis Services Get Data

In the Query Editor I create queries that pull in the csv files that I created earlier for DimProduct, DimCustomer and FactSales:

aasimport

Query Editor

Note, whilst it’s relatively straight forward to import csv files into Azure Analysis Services from Data Lake Store, my colleague Kay Unkroth wrote a great article that makes this much easier, and I use this method in my solution. Please see this article for further details.

Once the tables have been imported into Azure Analysis Services, it’s then a simple feat to define our star schema and create a couple of measures:

simpleschema

Simple Star Schema (No Date Dimension Yet!)

We then publish our Analysis Services model to the Azure Analysis Services Server we created in part 1, and connect to it using Power BI:

powerbiexample

Power BI Example

That’s it, all done!

Not quite…

Refresh and Orchestration

So we’ve shown now that you can ingest, process and serve data as dimensional constructs using Databricks, Data Lake Store and Analysis Services. However this isn’t at all useful if the pattern can’t be repeated on a schedule. From Part 1, we use Azure Data Factory to copy data from our sources and also to call our Databricks notebook that does the bulk of the processing. With our Analysis Services model now published, we simply need to extend our Data Factory pipeline to automate processing the model.

Logic Apps

There are a few methods out there for refreshing an Azure Analysis Services cube, including this one here. However I particularly like the use of Azure Logic Apps for a code-lite approach to orchestration. Using Logic Apps I can call the Azure Analysis Services API on demand to process the model (refresh with latest data from our data store). The Logic App presents a URI that I can then call a POST against that triggers the processing.

Jorg Klein did an excellent post on this subject here, and it’s his method I use in the following example:

logicapps

Logic App Example

Once you’ve verified that the Logic App can call the Azure Analysis Services refresh API successfully, you simply need to embed it into the Data Factory workflow. This is simply a matter of using the Data Factory “Web” activity that is used to call the URI obtained from the Logic App you created above:

logicappPost

Logic App Post URL

Our final (simplified for this blog post) Data Factory looks like this, with the Web Activity highlighted.

datafactorywithweb

A simple test of the Data Factory pipeline verifies that all is working.

Conclusion

So, there you have it. My aim in this post was to see if we could create a simplified data warehouse-like approach that did away with a relational data warehouse platform yet still provided the ability to serve the various workloads of a modern data platform. By keeping the data all in one location (our data lake), we minimize the amount of data movement, thus simplifying many aspects, including governance and architecture complexity.

In terms of how we did it:

  1. Ingested data from source systems using Azure Data Factory, landing these as CSV files in Azure Data Lake Store
  2. Azure Databricks was then used to process the data and create our dimensional model, writing back the data files into Azure Data Lake Store
  3. Azure Analysis Services ingested the the dimensional files into its in-memory engine, presenting a user friendly view that can be consumed by BI tools
  4. Refresh of the Analysis Services model was achieved using Azure Logic Apps, with this component being added to our data pipeline in Azure Data Factory

Is This A Viable Approach?

Simply put, I believe the approach can work, however I think it is definitely dependent on specific scenarios. You can’t, or at least, not very easily, create “traditional” data warehouse elements such as Slowly Changing Dimensions in this approach. The example proposed in these articles is a simple star schema model, with a “rebuilt-every-load” approach being taken as our data sets are very small. For large, enterprise scale data warehouse solutions you need to work in different ways with Data Lake Store than we would do with a traditional data warehouse pipeline. There are many other factors to discuss that would affect your decision but these are out of scope for this particular article.

So, can we build a datawarehouse-less data warehouse?

Yes we can.

Should we build them this way?

It depends, and it’s definitely not for everyone. But the joy of cloud is you can try things out quickly and see if they work. If they don’t, tear it down and build it a different way. One definite benefit of this particular solution is that it allows you to get started quickly for an alpha or POC. Sure you might need a proper RDBMS data warehouse further down the line, but to keep things simple get the solution up and running using an approach such as suggested in this article and “back fill” in with a more robust pipeline once you’ve got your transformation code nailed down.

Happy building.

Further Reading

Azure Analysis Services With Azure Data Lake Store

Process Azure Analysis Services Using Logic Apps

Operationalize Databricks Notebooks Using Azure Data Factory

Building The Data Warehouse-less Data Warehouse (Part 1 of 2)

/ Mike / 2 Comments

*Update – part 2 of this series is now live, and can be found here*

In times of yore, those who maketh the houses of data would bring forth vast swathes of tables and hurl them down in the forts of staging. Here the ancient priests of Ee, Tee and El would perform arcane magicks and transform these rows of chaos into purest order. This order would be rebuilt into the fabled Data Warehouses, and all who looked upon them would gasp in awe and wonder.

But that was then. Today’s data world is different, isn’t it? Data is varied. It’s big and small, fast and slow. It’s tougher to wrangle and make into shapes fit for use. But through all of this, we still need the hallowed, fabled, data warehouse.

Or do we?

This post is basically me exploring a different approach to building a data warehouse that’s based on the data lake paradigm and a form of ELT (Extract, Transform and Load), but leaves out the actual data warehouse part. I’m still going to build a star schema, but it’s going to be file based, using modern data engineering tools to do the munging and “schema-tizing” before sucking into a semantic layer for reporting. It’s also me exploring the capabilities of my current favourite tool – Azure Databricks.

What are the potential benefits of this approach? A few spring to mind, such as cost, flexibility and simplicity. By keeping all the processing within the data lake means it’s easier to control and govern, and the reduced data movement (you’re not copying into a data warehouse) makes an altogether more simpler structure.

Conversely, I’m well aware that this approach brings it’s own challenges. Traditional data warehouse constructs like Slowly Changing Dimensions, Surrogate Keys and other elements of the Kimball checklist will be harder or even not possible with this, so it won’t suit every scenario.

My aim here though was simple – can we build a BI solution without the data warehouse element and is it a viable approach for certain scenarios?

In short, the solution looks like this:

conceptualmodeldwlessdw

File-based Data Warehouse Conceptual Model

The above construct largely follows the traditional ETL model with data flowing in from source systems, and comprises the following:

  1. Data ingested as raw files into a staging zone in the data lake
  2. Files processed using data engineering platform into cleansed outputs
  3. Scrubbed files then shaped and moved into relevant serving zones. In this example I’ve kept it simple, with one zone for the star schema files and one for a data assets folder that provides cleansed, curated data sets to be consumed by analysts and data scientists.
  4. The star schema files are subsequently loaded into a semantic layer for enterprise reporting and ad hoc slice n’ dice functionality, whilst the asset files are consumed using the variety of tools preferred by today’s analysts.

To bring this to life, I’ll be using a handful of Azure data services for the relevant solution components –

solutioncomps

Solution Components

In this example, I’ll be using an Azure SQL Database as my data source with the AdventureworksLT database.

Prerequisites

For each of the above, ensure you put everything in the same Azure region.

Extract

There are plenty of options in this space that could move data from source to my lake, including ETL tools such as SSIS, Talend and Azure Data Factory. For this example I’m using Azure Data Factory (version 2), with copy activities moving data from my source SQL database and dropping as *.csv files. I’m also taking advantage of the new Databricks functionality built into Azure Data Factory that allows me to call a Databricks Notebook as part of the data pipeline.

datafactory

Data Factory Copy Activity

The above data factory copies the source tables into my “raw” directory, and from there I process the files, with the end result being to create my dimension and fact files ready to be loaded into Azure Analysis Services.

files

Load Files Into Spark DataFrames

With this files safely copied into our raw landing zone, I can now extract the source tables directly into Spark DataFrames. An example is shown below for the product table. We create a DataFrame for each source file.

dataframesrpoduct

Example DataFrame Creation

Transform

With the DataFrames created, I then create temporary SQL tables from them so that we can use SQL code to define my dimension. You can of course manipulate them natively as DataFrames using Python/Scala/R if you’re more familiar with those languages. I’m a SQL dude, and am familiar in building data warehouse routines in SQL code so have opted for that method here.

createview

Create Temporary Views From DataFrames

With these views created we can use good ‘old SQL to create DataFrames that reflect the dimensions and facts we want to load into Azure Analysis Services.

exampledim

Dimension Example

and fact tables:

examplefact

Fact Example

When I run my notebook now I have my dimensional and fact tables created as Spark dataframes. In order for them to be consumed by Azure Analysis Services I need to write the dataframes into CSV files that can then be imported into my tabular model.

Output Dimension and Fact Files

Writing files back from Spark into csv wasn’t as seamless as I thought it would be. Whilst the commands are fairly straight forward, as Spark is a distributed system it writes multiple files as an output, including crc and SUCCESS metadata files. It also doesn’t name them as the file you specify, but instead names it based on the partition name.

We don’t need these files, and need a proper, consistent filename, so I wrote some extra code to rename and move the files back under our Data Warehouse directory.

writetofile

Writing Out To CSV

With all this done, it leaves us nicely with a set of files ready for ingestion into Azure Analysis Services, which is the subject of Part 2 of this series.

outputfiles

Outputted Dimension And Fact Files

Coming in the second and final part of this series…

  • Build an Azure Analysis Services model directly off the dimension and fact files within the Data Lake Store
  • String it all together using Azure Data Factory

Part 2 is now live, and can be found here….

Introducing The Azure Data Architecture Guide

/ Mike / Leave a comment

Designing data-centric solutions in the cloud can be a challenge. Not only do we have the standard challenge of meeting customer requirements, but we also have to deal with an ever evolving data landscape of tools, paradigms and platforms. In the good old days of data warehousing for example, we had relational stores, often coupled with flat files/rogue Access databases etc, which were then fed nicely into another database using an ETL tool and then made reporting ready, often following one of the prevalent design methodologies for these solutions (Kimball, Inmon, Data Vault etc).

Fast forward to now (2018), and whilst the data warehouse is far from dead, the modern data platform is a much evolved beast featuring fast data, slow data, big data, small data, cold data, funny-shaped data, not-funny – you get the picture. All of it is needed to be processed in a way that can derive actionable insights and intelligence for us poor humans.

To help with this, Microsoft have released the Azure Data Architecture Guide, and it provides, to quote directly –

…a structured approach for designing data-centric solutions on Microsoft Azure. It is based on proven practices derived from customer engagements.

The guide’s main focus is the difference between relational and non-relational data, the design paradigms of both and the best practices, challenges and processes for designing these kinds of solutions.

It is by no means a deep-dive in the nuances of each component, but it gives good, broad content in this subject, allowing us to understand and appreciate the core concepts before diving into specific focus areas as required.

Recommended Reading.

Find it here – https://docs.microsoft.com/en-us/azure/architecture/data-guide/

And a PDF can be downloaded here.

 

Exam Tips For Getting Your MCSA (BI Reporting)

/ Mike / Leave a comment

To get your MCSA (BI Reporting) you need to take 2 exams – Analyzing and Visualizing Data With Power BI (70-778) and Analyzing and Visualizing Data with Excel (70-779). I recently took both exams at Microsoft Ready, and thought with them fresh in mind it was a good opportunity to “pass it on” and provide some tips and advice on how to achieve the certification. I wasn’t actually planning to take 70-779, but in a prep session we were informed that 70-779 is very similar to 70-778 so decided to take both.

It was good advice, and I managed to pass both in the same day, achieving my MCSA (BI Reporting) in the process.

mcsa-bi

MCSA (BI Reporting)

With this mind, I’ve added a couple of study recommendations plus some stand out items from both exams that I’d recommend you double down on when preparing.

Study Recommendation 1 – Take the Analyzing and Visualizing Data with Power BI on Edx. It’s free to take (or audit, as it’s referred to on the site) the course, and it provides an excellent foundation in all the skills tested in 70-778.

Study Recommendation 2 – Take the Analyzing and Visualizing Data with Excel on Edx. This is basically the sister courses of the Power BI, and it provides an excellent foundation in all the skills test in 70-779..

Study Recommendation 3 – Go through the Power BI Guided Learning. Like the above course, this provides an excellent Zero to Hero progression in Power BI, developing the hands on skills that are essential to knowledge retention.

After completing the above, below are some of my specific recommendations based on what I encountered in the exams:

  1. Know your DAX. Especially creating measures, calculated columns and calculated tables. Know the difference between CALCULATE, SUMX and similar operators. Here is a good place to start.
  2. Know your M, specifically around manipulating string values in columns. Check out the M language reference and play around with a few commands to get the feel for it.
  3. Know the difference between Import to Data Model and Import to Worksheet (70-779).
  4. Relationships in the Data Model – Know when you would use Bidirectional Filters, the difference between 1-1 and 1-many joins and specifically the impact of how the filter direction affects the visuals produced. There’s a great whitepaper on this subject here.
  5. Refreshing Power BI models in the Power BI Service – Understand what you can refresh from Onedrive, the difference between DirectQuery and Import modes.
  6. Pivot Tables and Pivot Charts in Excel. Understand the structure (Rows vs Columns vs Values). (70-779)
  7. Slicers and Filters. Swot up on Report Interactions and understand how to to turn this off and on to achieve the desired effect. Go through this tutorial.
  8. Know the main differences between Power BI Pro and Power BI Free and Power BI Premium. Know what each licencing option gives you, and it doesn’t. Start here.
  9. Sharing in Power BI – know how to do it, know the differences between the different sharing options. Read this for a good overview.
  10. Row Level Security – Understand the main concepts of Roles and Rules and how to implement it via the data model.
  11. Data Model sizing and performance best practices. MVP Avi Singh provides a great video on this here.
  12. Understand the kind of data sources supported in Power BI. I’d suggest playing through connecting to and manipulating the following sources to get a feel for the steps you undertake – SQL table, JSON file and Excel workbook.

These are the items I encountered when I took 70-778 and 70-779. There will obviously be some variation in what you will encounter, but hopefully this provides some good pointers in where focus. Hands down though the best preparation is going through both of the MOOCS identified at the beginning. They cover massive chunks of the material tested in the exam so I 100% recommend you work through these as a minimum.

Good luck!

*Addendum* Shout out to my colleague Dustin Ryan who’s produced a similar post for 70-778. I saw this posted on LinkedIn recently when was this one was nearly done so figured I’d still release it. Read both. They can only help you in the long run.

https://sqldusty.com/2017/08/23/preparing-for-microsoft-certification-exam-70-778-analyzing-and-visualizing-data-with-microsoft-power-bi/

 

SQL Server Options In Azure

/ Mike / Leave a comment

The data platform options in Azure are vast, and they grow and change with each month. Choosing the right database platform for your workloads can be a challenge in itself. This post aims to give some clarity as to the options available in the SQL Server space.

Before diving in, it’s worth clarifying the underlying platform options to be discussed. SQL Server in Azure comes in both Infrastructure As a Service (IaaS) and Platform As a Service (PaaS) flavors, which each providing different benefits depending on your specific needs. This is best summarized in the graphic below:

sqliaasoptions

SQL Server IaaS & PaaS

Infrastructure As A Service Options

SQL Server In Azure VM

As simple as it sounds, you can run SQL Server “as is”, running the full engine on a Windows or  Linux virtual machine, and also in a Docker container. This option is exactly the same as the one you’d run on premise, with the full SQL Server feature set, including High Availability, Security and various other features depending on the edition you choose.

If you need full control over/access to the OS, need to run apps or agents alongside the database, and basically want to manage all aspects of your solution, then SQL Server IaaS is the right solution.

This SQL Server option can be accessed from the Azure marketplace, with many editions available depending on your needs.

Billing in this model comes in two flavors too, Bring Your Own Licence (BYOL) where you provide your own SQL licence and just pay for the underlying compute/storage, or Pay As You Go where you pay the SQL licence per minute the machine is running for.

Platform as a Service (PaaS) Options

Along with the full control of SQL Server IaaS, you also have several PaaS options. These provide much better total cost of ownership (TCO) as much of the daily administration is handled by the Azure platform, so things like backups, high availability, performance tuning and monitoring are all abstracted away, allowing you to just focus on building/using your application.

 

sqlpassoptions

SQL PaaS Options

SQL Database

The first of the pure PaaS offerings, (sometimes called Database As a Service (DBaaS)), SQL Database offers the power of the SQL Server engine, but without the management overhead that comes with maintaining a full SQL Server instance.

As a DBaaS, SQL Database brings with it many features, including dynamic provisioning and resizing, built in High Availability, automatic backups, point-in-time restore and active geo-replication. As Microsoft assumes much of the daily maintenance work, this frees you up to realize cost or operational benefits that you wouldn’t have experienced with your on-premise or hosted solution.

Unlike the IaaS option, where you choose the virtual machine that your instance will reside on (with associated cpus, ram etc), SQL Database instead comes in different tiers, from Basic through to Premium. Rather than choosing specific hardware items like RAM, SQL Database tiers are measured in Database Throughput Units (DTUs), with the underlying specifications abstracted away.

Read here for more details on how to choose the best tier for your application.

There is a small subset of features not available or not applicable in SQL Database compared to SQL Server. Please check here and here.

SQL Database Managed Instances (Preview)

Designed to minimize the challenges of migrating applications to a SQL Database environment without having to perform application rewrites, SQL Managed Instance is an extension to SQL Database that offers the full SQL Server programming surface and includes several native SQL Server features:

  • Native Backup and Restore
  • Cross Database queries and transactions
  • Security features – Transparent Data Encryption, SQL Audit, Always Encrypted and Dynamic Data Masking
  • SQL Agent, DBMail and Alerts
  • Change Data Capture, Service Broker, Transactional Replication and CLR
  • DMVs, XEvents and Query Store

On top of this, SQL Managed Instance offers full security and isolation, with SQL Managed Instance being behind their own virtual network (vnet) within Azure (this is now also available for SQL Database).

Currently in private preview, with public preview due shortly, SQL Managed Instance is a great way to get started moving data to the cloud that combines the benefits of both PaaS and IaaS SQL Server models without having to make changes to the affected application. Microsoft have also created the Azure Data Migration Service to make the migration as seamless as possible.

SQL Database Managed Instance also provides an added incentive to move to the cloud with the Azure Hybrid Cloud Benefit for SQL Server. This allows you to move your on-premise SQL Servers to Azure, and only pay for the compute and storage. See here for more details.

SQL Database Managed Instance is going to be a real game changer in this space in my opinion. My colleague James Serra has created an excellent deck that goes into more details here.

SQL Database Elastic Pools

Whilst not technically a different type of SQL Database offering, Elastic Pools provides the ability to manage multiple SQL Databases that have a variable and unpredictable workload. SQL Databases in an Elastic Pool are allocated elastic Database Throughput Units (eDTUs) that dynamically scale the databases within the pool to meet the required performance demands.

Elastic Pools are ideal for multi-tenancy environments where the workload can’t be predicted, but you don’t want to have to over provision for those “just in case” moments.

SQL Data Warehouse

SQL Data Warehouse, whilst is “relational” in that it has tables with relations between them, is a different concept to the options above. SQL Data Warehouse is what is known as an MPP (Massively Parallel Processing) solution, designed for heavy duty data processing and querying at scale, the likes you’d see in a data warehouse or similar analytics solution.

SQL Data Warehouse could easily be the subject of a full article all on its own. This platform provides a fully scalable analytics engine where the compute and storage are scaled independently, meaning you’re not fixed into certain configurations that are over specced, thus providing greater TCO benefits. With the underlying Polybase engine supporting it, SQL Data Warehouse is a must-have component in many modern data warehouse architectures within Azure.

Read here for more information about SQL Data Warehouse use cases and design patterns.

Honorable Mentions

This post is specifically around SQL Server options within Azure, however I wouldn’t be doing justice to the platform if I didn’t mention the other database options available, and will be covered in future posts:

  • Cosmos DB – A globally distributed, multi-mode database service that supports SQL, Graph, Cassandra, MongoDB and Table APIs.
  • Azure Database for MySQL – Exactly as it says on the tin. This is another PaaS offering that provisions a MySQL instance.
  • Azure Database for PostgreSQL – As above, this PaaS offering provides PostgreSQL functionality, all managed by the Azure platform.

Which Should I Choose?

There are many factors to consider when choosing a relational database service in Azure, including cost, control, workload type, governance requirements and many more. As a general rule, if you need to have full control over your environment, with a full feature set, then SQL Server 2017 as a virtual machine or container is the way to go. For applications born in the cloud that just need the database engine and don’t want or need the hassle of maintaining the database, then SQL Database or SQL Database Managed Instance are excellent options. Again, if you need that elasticity that comes with hosting a multi tenant or highly variable environment, then SQL Database Elastic Pools is the option for you.

The real game changer now is SQL Managed Instances. Offering a full SQL Server feature set, but with all the benefits of PaaS, this option is great for those looking for a seamless move from on-premise to the cloud.

Further Reading

SQL Database vs SQL Server

SQL Data Warehouse vs SQL Database

SQL Managed Instances

 

 

 

 

Getting Started with SQL Operations Studio

/ Mike / Leave a comment

I’m a fan of new shiny things, and as a former SQL Server DBA the release of SQL Operations Studio definitely peaked my interest.

So, in the words of the Cat from Red Dwarf, “So what is it?”

(It’s not a White Hole…just in case you were wondering…)

The best description comes straight from the product team themselves, see here:

SQL Operations Studio (preview) offers a modern, keyboard-focused T-SQL coding experience that makes your everyday tasks easier with built-in features, such as multiple tab windows, a rich T-SQL editor, IntelliSense, keyword completion, code snippets, code navigation, and source control integration (Git). Run on-demand T-SQL queries, view and save results as text, JSON, or Excel. Edit data, organize your favorite database connections, and browse database objects in a familiar object browsing experience.

So, it’s a lightweight, slimmed down, better looking cousin of SQL Server Management Studio. In fact, my first thoughts when I saw this made me think of the approach that’s been taken with Visual Studio Code, wherein we’ve stripped out all the “bloat” of Visual Studio to focus primarily on the code side of things, making it a much faster, simpler experience.

It’s still in preview, but is already looking really slick. I’ve had a play around with it on a project I’m working on right now and here’re some stand out thoughts:

It Looks Really Nice

Server Dashboard

Server Dashboard

Like Visual Studio Code it’s got a fresh, clean feel about it.  You can quickly dive into deeper content (similar to SQL Server Management Studio) and also customize the look and feel and suit your personal tastes.

Intellisense Works (I used to have so much trouble with this – thank the heavens for Red Gate)

intellisense

Intellisense Example

Intellisense works out of the box, as should be expected.

You Can Create Your Own Insight Widgets and Dashboards

addedwidget

Database Dashboard Showing Slow Query Widget

You can create your own custom widgets, and there’s also some Out-of-the-Box ones already available. The widget above shows the Top Worse Performing Queries, and is already available to use. See here for information on setting up the widget.

Which can be Further Customized:

sqlopswithdatabasetasks

Database Dashboard

In the above example, I’ve customized the Database Dashboard for my TutorialDB to show both the Tasks widget and Slow Queries widget. This is based on the tutorial here.

Source Control Integration

A must have is source control integration, and the preview offering of SQL Operations Studio supports Git for version/source control.

GitIntegration

Git Integration

See here for more information on setting up with Git.

Integrated Terminal

And finally, just like Visual Studio Code, you have support for Integrated Terminal, so you can interact directly with Powershell, Command Prompt and GitBash (at the time of writing). A lot of my Azure work involves interacting with Powershell so this is a really useful feature, plus the ability to work natively with SQLCMD, bcp etc is great.

In the example below I’ve also customized the theme as I prefer the darker themes in VS to the light ones.

TerminalSQLOps

Integrated Terminal Set For Powershell

Other Stuff

I’ve only lightly touched on the features available at Preview. As well as those above, the current version includes, amongst others:

  • Code Snippets
  • Save Results as Text, JSON or Excel
  • Server Groups
  • Edit Data

 

Summary

SQL Operations Studio is in public preview (my version is 0.23) still, so it’s not fair to compare it directly to SQL Server Management Studio (SSMS) at this point. I think even when generally available, it should still be considered a separate beast to SSMS, as Visual Studio is considered different to Visual Studio Code.

As it stands right now, it’s very clean and slick, and has some great functionality already. I can see definite use cases for this where developers and DBAs want to work in a lightweight code-focused editor that provides all the key functionality that’s required to work with and administer SQL instances. Time will tell if it’s sufficient to pull people away from the tried and trusted SSMS, and I’ll look to do a follow up post when we’re at GA.

Further Reading

SQL Operations Studio (Preview)

A Lap Around SQL Operations Studio – Channel 9

So What’s SQL Operations Studio?

SQL Operations Studio FAQs

Bugs/Suggestions

Incremental ETL Processing With Azure Data Factory v2

/ Mike / 2 Comments

Data Factory V2 was announced at Ignite 2017 and brought with it a host of new capabilities:

  • Lift your SSIS workloads into Data Factory and run using the new Integrated Runtime (IR)
  • Ability to schedule  Data Factory using wall-clock timers or on-demand via event generation
  • Introducing the first proper separation of Control Flow and Data Flow to allow more complex orchestrations such as looping,  branching and other conditional flows
  • Incremental Loads using the new Lookup Activity

And it’s this last item that today’s article is about.

It’s fair to say that in its initial incarnation, Data Factory didn’t allow for more traditional ETL workloads without some complex coding (more than you were used to if you came from the world of SSIS and similar ETL tools). For the big data focused ELT workloads where data is moved between data services (SQL Server, Blob Storage, HDInsight and so forth) and activities applied whilst the data is in place (SQL queries, Hive, USQL, Spark) Data Factory V1 really excelled, but for those who wanted to move their traditional ETL delta extracts to Data Factory, it wasn’t quite there.

In this new public preview the product team have taken great steps in remedying this, allowing ETL developers to implement proper incremental loading patterns with their relational data warehouses.  It’s also worth knowing I’ve seen where Data Factory is going, and it’s looking amazing…

The following example is based on the official tutorial here. The differences in this example are based on the scenario where you wish to perform incremental extracts from a source database to a staging area inside another database. This example uses Azure SQL Database as both the source and sink, but can be adapted for other data sources.

The solution files used in this example can be found here

Prerequisites

This example assumes you have previous experience with Data Factory, and doesn’t spend time explaining core concepts. For an overview of Data Factory concepts, please see here.

So for today, we need the following prerequisites:

  • An Azure Subscription
  • An Azure SQL Database instance setup using the AdventureWorksLT sample database

That’s it!

Incremental Loading in Data Factory v2

The diagram demonstrates a high level overview of the process, and should be familiar to those who have built similar data flows with other ETL tools such as SSIS:

advv2incloadingoverview

Incremental Loading Overview

Process

There are four main steps to this process to create an end to end incremental extract.

  1. Identify the trigger column. In the Data Factory documentation this is referred to as the Watermark column so I’ll use this latter term for consistency going forwards. This column is one that can be used to filter new or updated records for each run. This column is normally an automatically updating datetime column (e.g. Modified_Date_Time) or an ever increasing integer. We use the maximum value of this column as the watermark.
  2. Create a data store to hold the watermark value. In this example we store the watermark value in our SQL Database.
  3. Create a pipeline that does the following:
    • Creates two Lookup Activities. The first looks up the last watermark value and the second retrieves the current watermark value.
    • Create a Copy activity copies rows from the source where any watermark values are greater than the old watermark value. These delta rows are then written to our target table.
  4. Create a stored procedure that updates the watermark value, ready for the next run.

Building the Solution

Create a Staging Table

In this example, we’ll use the SalesOrderDetail table in the AdventureWorksLT database:

salesorderdetail

SalesOrderDetail

And we will use the ModifiedDate as the watermark column.

We therefore need to create a target or “staging” table to load our delta rows into.

Run the following SQL in your created database to create a staging version of the SalesOrderDetails table:

CREATE TABLE [SalesLT].[SalesOrderDetail_Staging]

(

[SalesOrderID] [int] NOT NULL,

[SalesOrderDetailID] [int] NOT NULL,

[OrderQty] [smallint] NOT NULL,

[ProductID] [int] NOT NULL, [UnitPrice] [money] NOT NULL,

[UnitPriceDiscount] [money] NOT NULL,

[LineTotal] [money] NULL,

[rowguid] [uniqueidentifier] NOT NULL,

[ModifiedDate] [datetime] NOT NULL,

[ExtractDate] [datetime] Default Getdate()

)

Create a table for our watermark values

Run the following command in your SQL Database to create a table named watermark that will store our watermark value:

create table watermark
(

TableName varchar(255),
WatermarkValue datetime,
);

Set the default value of the watermark with the name of our source table. In this example, the table name SalesOrderDetail.

Insert into watermarktable
values (‘SalesLT.SalesOrderDetail’, ‘1-jan-2017’)

Create a stored procedure in our SQL Database:

This stored procedure is used to update the watermark table when new rows have been extracted.

CREATE PROCEDURE sp_write_watermark @LastModifiedtime datetime, @TableName varchar(50)
AS

BEGIN

UPDATE watermarktable
SET [WatermarkValue] = @LastModifiedtime
WHERE [TableName] = @TableName

END

Create Some Trigger Data

Run the following command on your SQL database to update a couple of rows in the source table. This is to validate the process is working correctly as it marks the rows as modified with today’s date, which is greater than the row in our watermark table. If the process is successful it will extract these changed rows.

update [SalesLT].[SalesOrderDetail]
set modifieddate = getdate()
where salesorderid = 71774

Create a Data Factory

Create a new Data Factory. For ease, do it via the portal following this guide.

(Ensure you create it using ADFv2):

adfv2

Creating a Data Factory via the Azure Portal

Create your Data Factory Artifacts

You will need to create the following (I’ve included my own samples in the link at the beginning of this article):

  • AzureSQLLinkedService
  • A source SQL dataset (for our source table)
  • A target SQL dataset (for our destination table)
  • A watermark dataset (that stores our watermark value entries
  • A pipeline that coordinates the activities

Modify the files to suit your needs and setup for your database server and database.

I won’t show the different JSON here, but just to highlight, the key area is the new Lookup Activity shown below:

pipelinelookupactivity

 

Create a folder on your root C Drive to hold the created JSON files

I created a folder called “adf” and put all my JSON files there:

adffolder

Deploy Data Factory Artifacts

For the current preview, you cannot deploy using the GUI, so you need to deploy programmatically. For this example I’m using Powershell. Note you will need to update your Powershell install with the latest cmdlets by running the following command:

Install-Module AzureRM

After updating the AzureRM cmdlets, run the following Powershell script below (attached at the start). This will deploy the necessary artifacts to your Data Factory.

powershellex2

Run the pipeline

Once deployed, you can run the deployed pipeline via Powershell with the following command:

$dataFactoryName = “[Your DATA FACTORY NAME]”
$resourceGroupName = “[Your RESOURCE GROUP NAME]”

$RunId = Invoke-AzureRmDataFactoryV2Pipeline -PipelineName “mainPipeline” -ResourceGroup $resourceGroupName -dataFactoryName $dataFactoryName

This fires off the pipeline. You can monitor its progress using Monitor & Manage:

minotoradf

Monitor Data Factory

And this allows you to see the status of the running pipelines:

pipelineruns

With the pipeline processed successfully,  I’ll check my database tables to check everything has updated correctly:

stagingdemo

Delta Rows Extracted

Bingo!

And the watermark table has been updated successfully:

watermarkupdate

Updated Watermark Table

This completes this article covering a simple ETL incremental extraction using the new Data Factory. The roadmap for this product is very exciting, and I encourage you to check out the links below for further reading:

Introduction to Data Factory v2

Data Factory Ignite 2017

 

Power BI Premium Vs Analysis Services

/ Mike / 8 Comments

What? Is that even a valid question?

At first glance this isn’t an obvious topic, but I’ve had a couple of conversations recently with partners that echoed some of my own thoughts about where and how Power BI Premium sits with Analysis Services.

Let’s recap what Power BI Premium brings in terms of performance enhancements (read about its wider capabilities here):

  • Increased dataset limits
  • Real time cache/pin to memory
  • Secondary model copies
  • Geo-replicas
  • Incremental/Dedicated Refreshes

With the new support for very large data sets, incremental refreshes etc, this has led to the following question being asked:

“If I have Power BI Premium with all these enhancements, why would I need Analysis Services?”

To me, there’s one main reason above all others why you would use Analysis Services in conjunction with Power BI, and you can skip to the summary to see it, but in order to answer this, let’s first look at the two products in more detail:

Power BI

Until recently, we had Power BI Pro (or Free) and Analysis Services. Both had quite a clear, defined place in the BI ecosystem. Power BI is described as the following:

“…a suite of business analytics tools to analyze data and share insights”

These tools include Power BI Desktop (a powerful desktop data mashup and reporting tool), Power BI Mobile (mobile apps allowing you to access reports from anywhere) and the Power BI Service (allows you to publish and share reports throughout the organisation).

So, Power BI allows users to ingest data from a variety of sources, mash it up, build some reports and publish them to the Power BI Service for sharing and collaboration.

Power BI Premium is an add on to Power BI Pro that brings dedicated capacity, performance and scalability (see earlier in this article).

Analysis Services

With Analysis Services, you can mashup and combine data from multiple sources, define metrics, and secure your data in a single, trusted semantic data model.

Sound familiar?

In many ways, Power BI and Analysis Services are very similar. In fact, Power BI has at its heart a Tabular Analysis Services engine. When you ingest and mash up data into Power BI Desktop, you’re actually populating a local version of Analysis Services.

In fact with both tools you have very similar features:

  • Create hierarchies
  • Measures
  • Calculated columns
  • Row Level Security
  • Live Connection/Direct Querying

Data Visualization and reporting aside (Power BI does this, Analysis Services doesn’t – it’s not a reporting tool) there are also differences, but the lines have become blurred in recent times.

The Main Difference

The key difference is that with a data model created in Power BI directly, it’s essentially a closed model to Power BI only.  Users can create pages (reports) in Power BI Desktop with multiple visualizations and then publish this workbook to the Power BI Service. Within the Service itself, users can edit the published reports on this dataset as well as adding new ones:

EditReportPowerBI

Edit Report In Power BI Service

The point here is that this model and its data can be reused within and by Power BI only. Users must login to Power BI to edit the report, or they can publish a Power BI Desktop file as a central model and connect to it as a Power Service Live Connection. All of this functionality is pure Power BI.

Where Analysis Services differs is that it is essentially an open model. Yes, you create a data model by ingesting data and creating a user-friendly reporting model in exactly the same way you do with Power BI, but that’s where you stop. You publish the Analysis Services model as a central, trusted data source and – and this it the crux of the matter – ANY tool that can submit DAX or MDX can use your Analysis Services model and get exactly the same answer. This is the ultimate “single version of the truth” that is the goal of so many BI projects. You create your central model, publish it, then connect to it from any of the following tools, plus many more:

 

Summary

In the end, Power BI Premium on its own is a compelling option if you’re just a Power BI shop (and Excel, sort of) and nothing else. Your analysts and developers can develop Power BI models in Desktop, and these models can be used to create reports in the Service, or from Power BI Desktop using the Power BI Service Live Connection. My advice in this scenario is to start with Power BI as your data models, especially if your models are small or moderate in size, then consider moving to Analysis Services as a scaling up option. This is an especially appealing option now with the release of the Analysis Services Web Designer, which allows you to publish Power BI workbooks to Analysis Services and create a data model from them. This is an ideal scenario where you’re running a PoC and want to promote it to something more “enterprise”.

ScaleUpAAS

Scale Up Power BI to Analysis Services

 

However, if you want a central data model to act as the single version of the truth and have many different tools in use across the organization, then Analysis Services is your friend:

aaswithpowerbi

Power BI & Other Tools With Analysis Services

In conclusion, I recommend Analysis Services as a key component for any relational data warehouse platform in combination with Power BI. Whilst the decision isn’t as clear cut if you only use Power BI, the ability to create a completely abstracted, semantic layer that serves as your golden view of data regardless of what visualization tool is used is a point that can’t be over sold.

Agree? Disagree? Please feel free to comment below.

Related Links

Power BI Premium

Azure Analysis Services

Power BI Service Live Connection

Why Analysis Services

 

 

 

 

 

Creating Animated Reports In Power BI With The Drilldown Player Custom Visual

/ Mike / Leave a comment

This is cool…

Chris Webb's BI Blog

Last week I had the chance to do something I have not done before: build a Power BI report to be displayed on a big screen hanging on a wall. To make up for the loss of user interactivity, I used the new Drilldown Player custom visual to cycle through different selections and display a new slice of data every few seconds; Devin Knight’s blog post here has a great summary of how to use it. However I wasn’t happy about the look of the Drilldown Player visual in this particular report: the play/stop/pause buttons aren’t much use if you can’t click on them and the visual doesn’t show all of the values that it is cycling through. As a result I hid the visual behind another one and came up with a different way of displaying the currently-displayed selection.

Here’s a simple example of what I did. Imagine you…

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