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The Definitive Guide to Power Query (M)

You're reading from  The Definitive Guide to Power Query (M)

Product type Book
Published in Mar 2024
Publisher Packt
ISBN-13 9781835089729
Pages 758 pages
Edition 1st Edition
Languages
Authors (3):
Gregory Deckler Gregory Deckler
Profile icon Gregory Deckler
Rick de Groot Rick de Groot
Profile icon Rick de Groot
Melissa de Korte Melissa de Korte
Profile icon Melissa de Korte
View More author details

Table of Contents (19) Chapters

Preface Introducing M Working with Power Query/M Accessing and Combining Data Understanding Values and Expressions Understanding Data Types Structured Values Conceptualizing M Working with Nested Structures Parameters and Custom Functions Dealing with Dates, Times, and Durations Comparers, Replacers, Combiners, and Splitters Handling Errors and Debugging Iteration and Recursion Troublesome Data Patterns Optimizing Performance Enabling Extensions Other Books You May Enjoy
Index

Accessing databases and cubes

Just as the standard M function library supports many different standard file formats, there are also core functions for accessing a variety of different industry-standard database/cube formats. Here we use the term cube to refer to database systems classified as Online Analytics Processing (OLAP) systems. The term database refers to relational databases classified as Online Transactional Processing (OLTP) systems. OLAP systems are suited for the multi-dimensional analysis of data while OLTP systems are suited for transactional operations.

OLTP systems tend to use highly normalized data structures that value the efficiency of data storage and speed of write operations over other concerns. Think high-transaction scenarios such as inventory management within a warehouse or retail sales. Conversely, OLAP systems aggregate (de-normalize) historical information and value the speed of read operations and the efficiency of analysis and reporting.

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