Karel van der Walt
Data Architect at ACPAS
Karel has participated in all aspects of the solutions lifecycle from problem structuring, feasibility, solutions architecture selection, technology scanning, negotiating with vendors, implementation, deployment and user support.
These solutions entailed products for desktop, terminals, client/server, dynamic web content and multi-tier web applications addressing persistence using XBase libraries, RDMS’s (Oracle, MS, Sybase, Interbase), ORM’s (Object-Relational Mappers), NoSQL, XML-technologies and object stores.
Developed products ranged from simple CRUD systems with extensive reporting to decision support systems with high-value-addition processing.
Solutions were developed with degrees of tool-support ranging from little or none up to fully generated solutions.
Karel closely tracks processes and methods and their match to organizational capacity.
Upcoming presentations
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Past presentations
Modularizing computation via Common Table Expressions (CTEs)
Functional-declarative vs. Imperative styles of computation
SQL allows for a terse expression of computation via the declarative style.
PostgreSQL lateral joins and set-returning functions remove the need for explicit iteration in computation.
SQL Common Table Expression (CTEs) - and some PostgreSQL-specific features - allow for new modes of modularisation of a computation.
This modularised computation still follows the economy ...
Oct 5 2021
From models to hosted OpenAPI Specification (OAS)
Rapid OpenAPI with PostgreSQL, JSON, PostgREST, Swagger UI & NGINX
Translate a data model of a domain into a hosted, fully functional OpenAPI Specification (OAS)
with minimal coding by integrating PostgreSQL with PostgREST and NGINX.
This presentation goes beyond a trivial CRUD (Create/Read/Update/Delete) API reflected from the schema,
to a State Model of a domain entity and its life cycle. It is rather the PostgreSQL func...
Oct 8 2019