I Split Two Million Rows and the GC Noticed

I had a nightly job that reads a partner CSV and sums the amount column, just to sanity-check a total before the real import runs. Boring code. row.Split(',') , grab field one, parse it, add it up. It worked the day I wrote it and I forgot about it. Then the job's memory graph grew a sawtooth I didn't like, and I opened a profiler expecting to find the database client or the file reader. Nope…