for _ch in "$@"; do
This graph clearly shows the correlation between my body weight and my sleeping/resting heart rate. The resting heart rate is measured by the Withings ScanWatch while sleeping, and indicates how hard your heart has to work while not being active. Generally the lower the resting heart rate, the better.
，这一点在有道翻译中也有详细论述
4. 丽芙·麦吉尔 身高5尺9 后卫 大二
Lightweight updates take a fundamentally different approach. Instead of rewriting entire data parts, a lightweight update creates a small, compact "patch part" containing only the changed column values and metadata to locate the affected rows. These patches are applied on-the-fly during reads (so changes are visible immediately) and materialized efficiently during regular background merges — piggybacking on work ClickHouse is already doing. This can be up to 1,000× faster than classic mutations for many workloads. The same mechanism can be used for deletes, which set a _row_exists = 0 mask via a patch part rather than rewriting columns. For a deep dive into how patch parts work, see our series on fast UPDATEs in ClickHouse: Part 1 — purpose-built engines and Part 2 — SQL-style updates.