Your Memory Configuration Could Slow Down Your System

David Klee warns against just throwing memory into servers willy-nilly:

An example of this is if you wish to configure 384GB of RAM on a new server. The server has 24 memory slots. You could populate each of the memory slots with 16GB sticks of memory to get to the 384GB total. Or, you could spend a bit more money to buy 32GB sticks of memory and only fill up half of the memory slots. Your outcome is the same amount of RAM. Your price tag on the memory is slightly higher than the relatively cheaper smaller sticks.

In this configuration, your 16GB DIMM configuration runs the memory 22% slower than if you buy the higher density sticks. Check out page 63 of the server build guide for an HPE Proliant DL380 Gen9 server. The fully populated 16GB stick configuration runs the memory at 1866 MHz. If you only fill in the 32GB sticks on half the slots, the memory runs at 2400 MHz.

Very interesting information.

Cleaning Up LOB

Raul Gonzalez reminds us that rebuilding a clustered index onto a new filegroup doesn’t move LOB data:

In previous posts I have explained how having dedicated filegroups for user data can improve our RTO by, in case of disaster, recovering critical data first and then the rest.

The thing is when you deal with databases which were not created this way, you need to move the data from one filegroup to another before you can apply this kind of techniques.

Here is where this post can show you one of the gotchas you can find during this process.

Read on for a demo of this.

Steps Recorder

Monica Rathbun shows how to use the Steps Recorder in Windows:

Windows PSR “Problem Steps Recorder”.  It’s a nifty tool that helps you trouble shoot a computer problem by recording step by step what the user is doing.

How to:

  • Go to Start

  • Windows Accessories

  • Steps Recorder or Problem Steps Recorder depending on Windows version

  • Select Start Record (App will popup)

That’s a new one on me; click through to check it out.

NOLOCK On CTEs

Erik Darling shows how the NOLOCK hint works with common table expressions:

So, for all you NOLOCKers out there, you can now save yourselves oodles of time by only using the hint in outer references to your CTEs and Views.

Congratulations, I suppose.

(Please stop using NOLOCK.)

Agreed, whenever possible.

Converting To Local Time In M

Chris Webb shows how to convert a datetime from UTC to your local time zone using M:

Here’s a brief explanation of what the query does:

  • First it reads the times from the Excel table and sets the Time column to be datetime data type

  • It then creates a new column called UTC and then takes the values in the Time column and converts them to datetimezone values, using the DateTime.AddZone() function to add a time zone offset of 0 hours, making them UTC times

  • Finally it creates a column called Local and converts the UTC times to my PC’s local time zone using the DateTimeZone.ToLocal() function

There are some limitations to what it does, so you can’t convert to just any time zone while still retaining Daylight Savings Time awareness.

Attribute Slicer

Devin Knight continues his Power BI custom visuals series:

In this module you will learn how to use the Attribute Slicer Power BI Custom Visual.  Using the Attribute Slicer you have the ability to filter your entire report while also being able to visibly see a measure value associated with each attribute.

Click through for the video as well as more details.  This looks like a very interesting way of integrating a slicer with some important metric, like maybe including dollar amounts per sales region and then filtering by specific regions to show more detailed analyses.

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