Segment Merge

Kloudfuse stores telemetry in Pinot segments that each stream partition seals at a fixed size or age. Over time a busy table accumulates many moderately sized segments, and every segment adds memory on the Pinot controller and servers, plus planning work on every query. Segment merge runs as a background Pinot minion task that combines consecutive sealed segments of a partition into larger ones, without changing any rows. The one exception is the metrics rollup table, whose merges, since 4.4.0, delete the rows of legacy resolutions by default; see Merge the metrics rollup table. You can run it on a schedule, on demand, or both.