Claude M. Schrader

Claude M. Schrader

Previously: 14 year career in IT. Currently: working with GIS, machine learning, and raster imagery

Recent posts

ETL Transformation to Third Normal Form for Philadelphia Building Demolition Permits

Figure 5

This ETL transformation was performed as an exercise in demonstrating proficiency using SQL in the PostgreSQL relational database with the PostGIS spatial extensions. I selected a spatial dataset of building demolition permits to load into the database and normalize to Third Normal Form. Once in place, this data can be combined with a secondary dataset on children with elevated blood lead levels to investigate correlations between demolition activity and elevated lead levels.

Introduction to Using MongoDB with Spatial Data

NoSQL databases are unlike many traditional SQL databases. In this tutorial we will review the differences between NoSQL and relational databases such as PostgreSQL, the strengths and weaknesses of a NoSQL database, and the reasons you might choose to use or avoid a NoSQL database. We will also demonstrate executing both spatial and non-spatial queries in MongoDB

Issues Surrounding the Release of Cellular Location Data

Through Spring and Summer 2018, a network of companies buying and selling access to the location of every customer of the four major carriers has been partially unveiled. Despite clear federal regulations governing receiving consent before providing access to customer data, some companies had rather loose consent policies.