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Tanel Poder

tanelpoder.com

- Linux, Oracle, SQL performance tuning and troubleshooting training & writing.

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1

Why SELECT * is bad for SQL performance (2020)

Here’s a list of reasons why SELECT * is bad for SQL performance, assuming that your application doesn’t actually need all the columns. When I write production code, I explicitly specify the columns of interest in the select-list (projection), not only for performance reasons, but also for application reliability…

2

Generate QR Codes with Pure SQL in PostgreSQL

As my cat woke me up way too early for a Saturday morning, I decided to put all this extra time (and my ChatGPT Pro subscription) into good use and generated a QR-code generator for PostgreSQL, written as a single pure SQL statement. No external libraries or Postgres extension installation needed! The pqr.sql example…