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Day: February 13, 2017

MDX Calculation Duration

Chris Webb wants to know how long specific MDX calculations take:

In my last two blog posts (see here and here) I showed how to use the Calculation Evaluation and Calculation Evaluation Detailed Information trace events to work out which MDX calculations are evaluated when a query runs in Analysis Services Multidimensional. That’s very useful, but wouldn’t it be great if you could work out how long any single calculation contributes to the overall duration of a query? If you could, it would make performance tuning MDX calculations much easier.

While you can’t get an exact amount of time taken for each calculation, the good news is that it is possible to get a duration rounded to the next second if your calculation is evaluated in bulk mode.

It’s an interesting way of backing into an answer.

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Power BI Quick Calc

Nicolo Grando talks about a couple of Power BI features, conditional formatting and Quick Calc:

If you select a text column you can:

  • Show only the first attribute
  • show only the last attribute
  • Count the attribute
  • Distinct count the attribute

If you select a numeric column you can:

  • Sum of value

  • find the minimum or maximum value

  • Average the value of column

  • standard deviation of value

  • Count the value

  • Distinct count of value

  • Variance fo value

  • Median of value

The screenshots are in Italian, but it’s pretty easy to get the context behind them.

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RStudio Connect

Jen Underwood discusses RStudio Connect:

RStudio officially introduced the newest product in RStudio’s product lineup: RStudio Connect. RStudio Connect is a new publishing platform for R that allows analytics users to share Shiny applications, R Markdown reports, dashboards, plots, and more. This release adds an improved user experience for parameterized R Markdown reports, simple button-click publishing from the RStudio IDE, scheduled execution and distribution of reports, and more security policies include hybrid data connections. Essentially RStudio Connect eases enterprise deployment scenarios.

Between what Microsoft is doing with its old Revolution Analytics holdings and what RStudio is doing, this is a great time to be an enterprise R customer.

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Temporal Tables

Alex Grinberg has a tutorial on temporal tables, including combining temporal tables with In-Memory OLTP:

Although the process of converting an In-Memory Optimized OLTP table to a system-versioned table is similar, there are some differences that we need to cover and demonstrate in this section.

You need to be aware of some specific details when converting the in-memory optimized table to the system-versioned table

Read on for those specifics.

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Troubleshooting SSRS 4xx Errors

Jeff Pries explains how to troubleshoot various Reporting Services configuration errors:

After installing SQL Server Reporting Services (SSRS), are you receiving an Error 404, Error 400, “Invalid Request” error, or “Bad Connection” error on first visiting the SSRS web portal (the error message seems to vary based on version, browser, and whether accessing via http/https or /reports vs /reportserver) ?

I’ve run into this a few times so I’m listing the steps I’ve used to fix it.  For me, the root cause of this error has been the SSRS Configuration Wizard automatically configuring SSRS to use HTTPS, but assigning an invalid machine SSL Certificate.  The fix is to self-generate a new and valid SSL certificate for the SSRS website to use.

Jeff then provides step-by-step instructions.

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Scaling Up R

Ginger Grant explains how to use SQL Server R Services to take advantage of server resources instead of running from your local machine:

Microsoft’s R Server contains some specialized functions which are not part of the standard CRAN R installation. One of the ScaleR functions, RxInSqlServer will allow code to be processed on the server from the client. To make this work, you must have R Server and R Client installed. If you are doing a test on a local machine, you will need both R Client and R Server installed on that computer.

Click through for a script which walks you through the process.

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Blocked Process Report: monitorLoop

Michael Swart explains what the “monitorLoop” attribute is on the blocked process report:

You won’t find too much explanation about that field in the official documentation but I believe I know what it means.

The blocked process report is closely tied to deadlock detection and it’s generated by the same process as the deadlock monitor. If you remember, the deadlock monitor runs frequently looking for deadlocks (which are just blocking chains in a circle). It runs every couple seconds when there are no deadlocks, and if it detects any, it runs a bit more frequently. Each time it runs it’s called a monitor loop. The monitorLoop is just a number that starts at zero when the server restarts and increments by one each time the monitor runs.

Read on for more details.

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Always Encrypted Data And SSMS

Justin Goodwin shows how to view Always Encrypted data from within Management Studio:

I am now able to view the encrypted data. Why is this?

Because I am connecting to the database from the database server, I have access to the Encryption Certificate that was generated. I can verify this by opening certmgr.msc and browsing to Personal -> Certificates:

Justin then goes on to show what happens when you don’t have access to the certificate and how to provide access to another machine.

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