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Day: September 21, 2017

Regular Expression Cheat Sheets

Published 2017-09-21 by Kevin Feasel

Mara Averick shows off a collection of regular expression guides:

There are helpful string-related R packages 📦, stringr (which is built on top of the more comprehensive stringi package) comes to mind. But, at some point in your computing life, you’re gonna need to get down with regular expressions.

And so, here’s a collection of some of the Regex-related links I’ve tweeted 🐦:

Click through for links to regular expression resources.

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Visualizing A Single Number

Published 2017-09-21 by Kevin Feasel

Tim Bock shows a dozen methods for visualizing a single number:

There are a number of situations in which it can be advantageous to create a visualization to represent a single number:

  • To communicate with less numerate viewers/readers;

  • Infographics and dashboards commonly use one important number;

  • To attract the attention of distracted or busy viewers/readers;

  • To add some humanity or “color”, to create an emotional connection;

  • Or to increase the redundancy of the presentation (see Improve the Quality of Data Visualizations Using Redundancy).

To a great extent, my favorite is the first.  There are good cases for many of the others—primarily the shock value of the uncountable pictogram—but typically, the best visualization is simple.

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Date Correlation Optimization

Published 2017-09-21 by Kevin Feasel

Monica Rathbun explains another quasi-hidden SQL Server configuration option:

According to MSDN – The DATE_CORRELATION_OPTIMIZATION database SET option improves the performance of queries that perform an equi-join between two tables whose date or datetime columns are correlated, and which specify a date restriction in the query predicate.

How many of you read what MSDN says and thinks “wuuuuuttt, English please”? I do.

Read on for the English translation.

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Dealing With Noisy Neighbors

Published 2017-09-21 by Kevin Feasel

Kevin Kline explains what Resource Governor does:

There are lots of ways to manage noisy neighbors. For example, you could spin up additional instances of SQL Server on a single physical or virtual machine (VM), and then segregate the applications to a distinct instance. You could also follow the old adage of “one application, one SQL Server” by putting the SQL Server onto its own machine, either physical or virtual. But that can get very expensive very quickly, depending on your licensing methodology.

If you’re running SQL Server 2008 or later, you might want to investigate Resource Governor as an alternative. Resource Governor lets you create limits on the amount of system resources a database and application can consume. On versions 2008 to 2012, Resource Governor can explicitly limit CPU and memory and, starting with version 2014, limit I/O consumption as well. This is powerful medicine for multi-tenant instances with noisy neighbors!

My response to noisy neighbors is to turn my music up really loud as a passive-aggressive response.  Oh, wait, wrong kind of noisy neighbor…  H/T SentryOne

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Creating Database Snapshots

Published 2017-09-21 by Kevin Feasel

David Fowler has a script which lets you create database snapshots easily:

The procedure takes two parameters,

@DatabaseList – a comma delimited string of database names, allows wildcards
@ListOnly – 1- a list of affected databases will be displayed but snapshots aren’t created.
0- Snapshots are created automatically DEFAULT

I’m a big fan of database snapshots in development and QA environments—take a snapshot, run a workload, revert the snapshot.

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