Author Archives: Jan Zedníček

About Jan Zedníček

My name is Jan Zedníček and I work as a freelancer. I have been working as a freelancer for many companies for more than 5 years. I used to work as a financial controller, analyst and manager at many different companies in field of banking and manufacturing. When I am not at work, I like playing volleyball, chess, doing a workout in the gym and I enjoy tasting of best quality rums. I am trying to summarize all my knowledge on this website not to forget them (because of the rum effect, you know =) and to put them forward to anyone. Don´t worry about asking for help or writing some comments.

Excel | Subtotal – 11 Functions in One

By | 23. 5. 2020

SUBTOTAL is a little strange function. There are 11 mathematical functions hiding inside it. We can calculate sum, arithmetic mean, spread, minimum/maximum and another statistic values using SUBTOTAL function. What’s more, we can limit whether we want to calculate even with hidden values which were hidden manually. All under roof of one function. SUBTOTAL –… Read More »

FILTER Functions for Power BI in DAX – Overview

By | 21. 3. 2020

FILTER functions (filtering functions) are used to get values from the table. Some functions enable additional filtering in a given table. These functions are often part of different functions as is nested parameter and enable dynamic calculations. They often serve as a value filter for function  CALCULATE. Mostly it is the case of typical member… Read More »

Aggregation in DAX – How Aggregations Work? + Function Overview

By | 21. 3. 2020

Aggregate functions in DAX language are used to get certain summarized or grouped data view. Thanks to this, we can edit high detail data in a certain column into more simple and reportable form using aggregation. We can for example sum up (SUM, SUMX) some financial metrics by individual category or express maximal/minimal (MAX, MAXX,… Read More »

DAX | SUM and SUMX – How to Perform Aggregation in DAX Language for Power BI

By | 11. 2. 2020

You probably noticed that there are many functions in DAX that are similar to Excel ones (as in article here). Contrary to Excel functions, DAX haves on strange thing. Some aggregate functions have another similar function ending with X – for example SUM and SUMX or COUNT and COUNTX. These functions often give same results… Read More »

SQL Indexes – Indexing Theory Simply, Balanced Tree, Heaps

By | 11. 2. 2020

Correct table indexing in SQL Server is a base for good database performance during querying. You need to understand how SQL Server stores data into tables/indexes if you want to create appropriate sql indexes. It is also important to know how to approach these data correctly during querying. How Does SQL Server Organize Data Physically?… Read More »