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Mala's Data Blog

My name is Malathi, a.k.a Mala - I am a DBA turned BI/Data Science person, working with SQL Server since 6.5. I am also founder of the Louisville SQL Server user group, organizer of 8 SQL Saturdays, Regional mentor for northeast, and 12-year PASS conference attendee. In my spare time I love to garden, travel, read, paint, and do yoga.

SQL Saturday Nashville 2018

I decided to go to the SQL Saturday at Nashville this year to get some good learning and networking in during frigid January. One of the reasons I wanted to go was that the line up for precons was amazing and I wanted to learn more on Azure particularly. I… Read more

0 comments, 127 reads

Posted in Mala's Data Blog on 15 January 2018

T-SQL Tuesday #97 Roundup: Learning goals for 2018

T-SQL Tuesday is a monthly blog party started by respected SQL Guru Adam Machanic. I was honored with hosting this month’s party. I picked a topic that is important for me at this time of the year – setting learning goals. I was surprised and somewhat overwhelmed to see the… Read more

0 comments, 350 reads

Posted in Mala's Data Blog on 18 December 2017

T-SQL Tuesday #97 – My learning plan

This month’s T-SQL Tuesday is hosted by…er..yours truly. I picked a topic that usually comes up for me every December – learning goals for the next year. This is the first time that I am blogging about it.

Usually this review is accompanied by a strange combination of imposter syndrome,… Read more

1 comments, 1,664 reads

Posted in Mala's Data Blog on 11 December 2017

T-SQL Tuesday #97 – Setting learning goals for 2018

This is my first opportunity hosting a T-SQL Tuesday and am super excited!!
T-SQL Tuesday is the brainchild of well respected SQL Guru and author of ‘sp_whois active’ – Adam Machanic (b|t).  Adam rightly predicted that we all could benefit from ‘a recurring, revolving blog party’…

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42 comments, 387 reads

Posted in Mala's Data Blog on 4 December 2017

TSQL Tuesday #96 – Folks who have made a difference

This month’s T-SQL Tuesday is hosted by Ewald Cress, and the topic is ‘Folks who have made a difference’. This is an opportunity – and right around thanksgiving – to give a shout-out to people who have made a difference in our careers and in the data community. To… Read more

1 comments, 207 reads

Posted in Mala's Data Blog on 14 November 2017

Dealing with disquiet

Last week I listened to a podcast from one of my best friends in the sql community – Kendra Little. In this podcast Kendra talks of her encounter with anxiety attacks and how she dealt with them. When I listened to her honest, moving story – my mind was filled… Read more

0 comments, 1,592 reads

Posted in Mala's Data Blog on 11 November 2017

PASS Summit 2017 – the best ever

I have been a PASS summit attendee for 14 years now. This year is my 15th. Every year is different – some years are better than others, some make you feel it wasn’t as good as usual. This year was an odd experience for me. Quite a number of my… Read more

0 comments, 318 reads

Posted in Mala's Data Blog on 5 November 2017

Understanding ANOVA

ANOVA – or analysis of variance, is a term given to a set of statistical models that are used to analyze differences among groups and if the differences are statistically significant to arrive at any conclusion. The models were developed by statistician and evolutionary biologist Ronald Fischer. To give a… Read more

0 comments, 1,626 reads

Posted in Mala's Data Blog on 9 October 2017

Box-and-whisker plot and data patterns with R and T-SQL

R is particularly good with drawing graphs with data. Some graphs are familiar to most DBAs as it has been things we have seen and used over time – bar charts, pie diagram and so on. Some are not. Understanding exploratory graphics is vitally important to the R programmer/data science… Read more

0 comments, 1,585 reads

Posted in Mala's Data Blog on 25 September 2017

Confidence Intervals for a proportion – using R

What is the difference between reading numbers as they are presented, and interpreting them in a mature, deeper way? One way perhaps to look at the latter is what statisticians call ‘confidence interval’.

Suppose I look at a sampling of 100 americans who are asked if they approve… Read more

0 comments, 965 reads

Posted in Mala's Data Blog on 18 September 2017

What is networking, really?

I am still trying to get up to speed on blogging after a gap. Today I managed to push myself to write some R code and test it, and it worked. Am getting there, although need more work to turn it into a blog post. So, here is another on… Read more

1 comments, 1,331 reads

Posted in Mala's Data Blog on 10 September 2017

14 years of Summit…

I have been trying to get my blogging going again after a gap of two months. It has been incredibly hard. To warm up, I decided to try some non technical posts. One of them is stuff I have been wanting to write a long time – with this year… Read more

1 comments, 281 reads

Posted in Mala's Data Blog on 4 September 2017

Getting back to blogging

The past two months have been very hectic for me. I had an unexpected job offer towards end of July, which I gladly accepted – that was followed by some much needed home renovation, and a long vacation/tour of the west coast with my beloved sister. All of this has… Read more

0 comments, 296 reads

Posted in Mala's Data Blog on 28 August 2017

Understanding Relative Risk – with T-SQL

In this post we will explore a common statistical term – Relative Risk, otherwise called Risk Factor. Relative Risk is a term that is important to understand when you are doing comparative studies of two groups that are different in some specific way. The most common usage of this is… Read more

2 comments, 1,661 reads

Posted in Mala's Data Blog on 19 June 2017

Cochran-Mantel-Haenzel Method with T-SQL and R – Part I

This test is an extension of the Chi Square test I blogged of earlier. This is applied when we have to compare two groups over several levels and comparison may involve a third variable.
Let us consider a cohort study as an example – we have two medications A and… Read more

0 comments, 321 reads

Posted in Mala's Data Blog on 12 June 2017

Dataset for Cochran-Mantel-Hanzel Test

Below is the script to create the table and dataset I used. This is just test data and not copied from anywhere.

USE [yourdb]
/****** Object: Table [dbo].[DrugResponse] Script Date: 6/12/2017 6:45:46 AM ******/
CREATE TABLE [dbo].[DrugResponse](…

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1 comments, 284 reads

Posted in Mala's Data Blog on 12 June 2017

Fischer’s Exact Test – with T-SQL and R

This post is a long overdue second part to the post on Chi Square Test that I did a few months ago.  This post addresses relationships between two categorical variables, but in cases where data is sparse, and the numbers (in any cell) are less than 5. The Chi Square… Read more

3 comments, 1,268 reads

Posted in Mala's Data Blog on 22 May 2017

SQL Saturday Louisville precon – interview Andy Leonard

This will be year #9 of sql saturdays in Louisville. Every year (starting with 3rd or 4th), it has been a tradition to do ‘precons’ on Fridays. For those who don’t know – Precons are day long paid trainings by an expert in the subject, held on the friday… Read more

0 comments, 310 reads

Posted in Mala's Data Blog on 8 May 2017

SQL Saturdays – down memory lane

A casual twitter-conversation with Karla Landrum and some other peeps led me down memory lane on older events. Our SQL Saturday at Louisville will be 9 years old this year. We were event #23, in 2009. SQL Saturdays started two years before, in 2007.

Our first event was held at… Read more

0 comments, 312 reads

Posted in Mala's Data Blog on 1 May 2017

The Birthday Problem – with T-SQL and R

When I was on SQLCruise recently – Buck Woody (b|t) made a interesting statement – that in a room of 23 people, there is over a 50% chance that  two or more have the same birthdays. And sure enough, we did end up having more than… Read more

1 comments, 1,690 reads

Posted in Mala's Data Blog on 24 April 2017

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