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Article on Modelling, Joins, Relationships and Different Schemas In Power BI

Data Modeling, Relationships, and Schemas in Data Analytics In the fields of data analytics, data warehousing, and database management, modeling and schema design are the fundamental pillars used to organize and query information efficiently. This article provides a comprehensive guide to these core concepts. 1. Data Modeling Data modeling is the architectural process of designing how data is stored, interconnected, and accessed within a system. Core Questions Addressed: Storage: What specific data points need to be captured? Structure: How should individual tables be organized? Connectivity: How do these tables interact with one another? Levels of Data Models: Conceptual Model: A high-level business perspective focusing on entities and their relationships, devoid of technical specifications. Logical Model: Defines specific attributes, keys, and relationships. It is independent of the Database Management System (DBMS). Physical Model: The actual implementation within a database, including technical details like indexes, partitions, and storage requirements. 2. Relationships Relationships define the logic of how data in one table corresponds to data in another. One-to-One (1:1): A single record in Table A relates to exactly one record in Table B. One-to-Many (1:M): The most common relationship; for example, one Customer can place many Orders . Many-to-Many (M:M): Multiple records in one table relate to multiple records in another. This requires a Junction Table (Bridge Table) to function. Example: One Student can enroll in many Courses, and one Course contains many Students. 3. SQL Joins Joins are used to combine rows from two or more tables based on a related column. Join Type Description Inner Join Returns only the records that have matching values in both tables. Left Join Returns all records from the left table and the matched records from the right. Right Join Returns all records from the right table and the matched records from the left. Full Outer Join Returns

2026-07-01 原文 →
AI 资讯

DATA MODELLING RELATIONSHIPS AND SCHEMAS IN POWER BI

INTRODUCTION When I started using Power BI, I only thought of visuals like charts and graphs. However, as I progressed, I discovered a great data dashboard is built on great data models. Data Modelling is the process of organizing your data tables and defining how they relate to each other so Power BI can combine them into meaningful reports and dashboards. Good, designed data makes it easier and faster to maintain. Why is data Modelling Important Well-organized data makes it easier to manage data. Reduction of the duplicates. Ensures data consistency. Understanding Relationships Relationships allow the data table to give communication using fields. For example, Customer Table stores all information about a customer. Product Table store product details Sales Table stores all information about the transactions. Power BI connects the information between the customer’s name and Customer Id rather than repeating them it connects the information using joins. Going through relationships I discovered schemes. Scheme is the way tables are organized in databases. There are different types of schemes e.g. Star Schema, snowflake schema and Flat table. Star Schema A star schema is a data model with one central fact table and dimension table surrounding it. Fact table A table that stores events, transactions of what happened. • Total sales • average sales • quantity sold Dimension table A dimension table describes the items in the fact table. The table contains descriptive information. • The customer table describes the customer • How much sales were made The fact table sits in the center, while the dimension tables surround it—forming a star. Dashboard designs A good dashboard has to fit one page. A dashboard should show critical information. Update automatically when data changes. Focus on data understanding and decision making. Conclusion Power BI taught me that a great report are built from a a great dashboard which is achieved by having great models. Structuring a data into

2026-07-01 原文 →
AI 资讯

The Supreme Court stops Trump’s attempt to end birthright citizenship

The Supreme Court upheld birthright citizenship, ruling 6-3 against President Donald Trump's effort to end the longstanding constitutional right via executive order. Birthright citizenship dates back to Reconstruction. Under the 14th Amendment, which was ratified in 1868 to guarantee citizenship and equal protection to the children of formerly enslaved people, anyone born in the United […]

2026-06-30 原文 →
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Bernie Sanders Saw This Coming

For decades, the senator has argued that concentrated wealth threatened American democracy. Now he’s betting that frustration with Big Tech, billionaires, and unchecked AI is reaching a tipping point.

2026-06-30 原文 →
AI 资讯

The First Visible LED Glowed Red

Look at almost any piece of electronics on your desk and you will find a small light staring back at you. A router with a row of blinking status lights. A power brick with a steady green dot. A development board with a tiny red point that flickers every time it does something. We barely notice these lights anymore, but each one descends from a single laboratory breakthrough in 1962, when an engineer at General Electric coaxed a sliver of semiconductor into glowing visible red for the first time. Who invented the first visible LED The engineer was Nick Holonyak Jr., a consulting scientist at General Electric's lab in Syracuse, New York, and a former student of John Bardeen, one of the inventors of the transistor. On October 9, 1962, Holonyak demonstrated the first practical visible-spectrum light-emitting diode. It emitted red light, and it worked at room temperature, which made it genuinely useful rather than a laboratory curiosity. What made his approach different was the material. Other researchers in the early 1960s were building diodes that emitted infrared light, which is invisible to the human eye. Holonyak gambled on a different alloy, gallium arsenide phosphide, and it paid off with the first light a person could actually see coming out of a semiconductor. He was so confident in the idea that he predicted LEDs would one day replace the incandescent bulb. At the time that sounded outlandish. Today it is simply how lighting works. Why a tiny red light mattered so much The incandescent bulb that Thomas Edison commercialized makes light by heating a filament until it glows. That is wildly inefficient, because most of the energy escapes as heat rather than light, and the filament eventually burns out. An LED works on a completely different principle. When current flows across a specially engineered semiconductor junction, electrons release their energy directly as photons. There is no filament to burn out, almost no wasted heat, and the device can switch on and o

2026-06-30 原文 →
AI 资讯

Abandoning Abstractions: Manually Crafting EtherNet/IP Packets Almost Broke Me

By RUGERO Tesla ( @404Saint ). There is a persistent illusion in Industrial Control Systems (ICS) security research: that high-level libraries, abstraction frameworks, or protocol tooling give you a real understanding of Operational Technology (OT) behavior. They don’t. They hide the architecture. Determined to understand what actually happens when a Programmable Logic Controller (PLC) receives a control-plane command, I built an EtherNet/IP and Common Industrial Protocol (CIP) sandbox from scratch. No Scapy. No protocol wrappers. Just raw sockets, a Linux loopback interface, a cpppo simulator, and a passive monitoring tool ( enip_monitor.py ) capturing traffic in real time. It looked clean on paper. Then I reached the application layer. And things stopped behaving like theory. The Reality of the “Industrial Abstraction Layer” If you come from Modbus or traditional IT networking, you’re used to linear memory spaces—fixed registers, predictable offsets, and flat addressing. EtherNet/IP and CIP discard that model entirely. Instead, they introduce a structured object system wrapped inside multiple encapsulation layers: +-----------------------------------------------------------+ | EtherNet/IP Encapsulation Header (24 bytes) | | → Session control, commands (0x0065, 0x006F) | +-----------------------------------------------------------+ | Common Packet Format (CPF) | | → Routing, addressing, and transport segmentation | +-----------------------------------------------------------+ | CIP Application Layer | | → Service codes (0x4C, 0x4D, 0x10, etc.) | +-----------------------------------------------------------+ To communicate with a PLC at the wire level, your code must: Establish a session using RegisterSession (0x0065) Wrap all subsequent requests in SendRRData (0x006F) Encode routing information inside CPF structures Construct symbolic or logical paths for the CIP Message Router Ensure strict byte alignment across nested payload layers A single mistake in any layer b

2026-06-30 原文 →
AI 资讯

Inside Target’s LLM-Based System for Semantic Matching in Marketing Forecast Pipelines

Target built a generative AI system to improve marketing campaign forecasting by retrieving and ranking similar historical campaigns. Using embeddings, vector search, and LLM ranking, it replaces rule-based workflows. Evaluation shows 75% top-1 and 100% top-3 coverage. The system reduces manual effort, improves consistency, and uses feedback loops to refine retrieval using campaign outcomes. By Leela Kumili

2026-06-29 原文 →
AI 资讯

Robot Police Officers

We’ve taken one small step towards robot police officers: a drone capable of disarming a suspect: In a June 22 video posted on the Sacramento County Sheriff’s Office’s Instagram page, an officer wearing goggles can be seen operating a drone to retrieve a knife from an armed suspect hiding inside a cluttered house. “After not responding to negotiators, a drone was deployed inside the residence,” the post says. “Drone pilots located the suspect hiding in a corner of a garage” and then used a high-powered magnet attached to the drone to grab the knife out of the suspect’s hand. In the video ­ which is soundtracked by the “Mission: Impossible” theme song—the intercepted knife can be seen spinning around in the air as the drone carries it back to the deputies...

2026-06-29 原文 →
AI 资讯

I timed stair carries on my commute ? the spreadsheet column mobility apps skip

I log commutes in a spreadsheet because mobility apps smooth over the ugly legs. Last week I added a column I should have tracked years ago: carry seconds ? time from curb to platform when stairs replace ramps. The hidden leg My one-wheel leg is fine on paper. Three metro exits on my route have no elevator during maintenance. Carrying a 14 kg wheel down 22 stairs does not show up in trip duration. It shows up in whether I arrive annoyed enough to skip coffee. What I logged (one week) Exit Stairs Carry time (s) Mood after (1-5) North gate 22 38 2 Side ramp (control) 0 8 4 East stairs 16 29 3 Battery delta on those days? Within noise. Mood delta? Not noise. A cheap decision rule I turned this into a go/no-go check before leaving: if stairs > 15 AND carry_weight_kg > 12: prefer transit-only or locker elif stairs > 0 AND wet_floor: walk the wheel (no riding in station) else: ride It is blunt. It works better than pretending every leg is rideable. Assumptions up front Wheel weight includes pads and charger pouch (~14 kg for my commuter setup). I am not timing competitive carries ? just whether I can do this daily without hating it. Your threshold differs if every exit has elevators. What I would do differently I would log carry seconds from day one, same tab as distance and battery percent. Range math without carry math is incomplete for anyone who mixes metro and one-wheel. I work around personal EVs and sometimes cross-check specs on the official Kingsong catalog. https://www.kingsong.com/collections/electric-unicycle

2026-06-29 原文 →