Workflow states are reference data with consequences. A helpdesk ships states like new, open, resolved and closed. Every ticket points at one, and each state names the one that usually comes next, so…
Every PostgreSQL database has a few queries the planner gets badly wrong. Not slow because they’re big. Slow because the planner guessed the wrong row count, picked a plan for ten rows, and got ten…
This case study takes four queries from LQO’s run of the Join Order Benchmark: 113 analytical queries over the IMDB movie database, real data with all its skew. The numbers come from the recorded run…
This case study comes from LQO’s own demo shop, the one lqo demo builds, and the numbers are from the recorded test run on GitHub. No customer is involved. The query pattern is a common one, though: a…
A customer calls support. Their credit limit was 100 yesterday and it’s 50 today, and nobody told them why. The support agent can see the 50. Everything else is spread across three services. The…
Prices change together. A new quarter’s price list touches every plan at once, and a half-applied list is worse than an old one: for a few minutes Pro might cost less than Basic. The list also has one…
At two in the morning an alert fires: the orders database is answering slowly, and order requests are timing out. The on-call engineer raises the database timeout from 5 seconds to 30 so requests stop…
An operations agent watches the product catalog. Its metrics show 4.1% of reads returning stale data, above the 2% target, so it shortens the catalog cache’s time-to-live from 300 seconds to 30…
CodeInstances v0.5.0 is about getting a run from where it failed to where someone can fix it. A test fails in CI at 3 a.m. The run is kept, but it’s sitting on a build machine that’s gone in an hour…
CodeInstances v0.6.0 adds fork. Replay runs a program against the whole recording. Fork runs it against the recording up to a step you pick, then lets it carry on from there. You get the past exactly…