Karel van der Walt

Data Architect at ACPAS

About

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.

Karel van der Walt has presented the following presentations

    Karel van der Walt Modularizing computation via Common Table Expressions (CTEs) at South Africa 2021
    Functional-declarative vs. Imperative styles of computation

    presented by Karel van der Walt

    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 ...

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    Tue 5 2021 Development
    Karel van der Walt From models to hosted OpenAPI Specification (OAS) at South Africa 2019
    Rapid OpenAPI with PostgreSQL, JSON, PostgREST, Swagger UI & NGINX

    presented by Karel van der Walt

    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...

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    Tue 8 2019 Development