A Valid Pricing Row Can Still Be Wrong

Sun, 15 Feb 2026 00:00:00 +0000

One row charges EUR 12 from zero through five kilograms. Another charges EUR 18 from four through ten. Give them different names and sequence numbers, attach them to the right tariff book, and both rows can be perfectly valid database records. At 4.5 kilograms, they still disagree about the base price. Adding them gives EUR 30, which nobody specified as the base rate.

Moving my private rating engine from expression definitions to explicit rows made this problem easier to inspect. It didn’t solve it by itself. I needed to decide which combinations should be impossible, which should remain valid drafts, and which should stop a ruleset from becoming executable.

Data-Integrity on Brian Faust

A Valid Pricing Row Can Still Be Wrong