2.9 SiLU（Swish）
Setting up your actual Sleep Routine takes a little more time and intention. A Dreamie Sleep Routine consists of multiple steps, which you can use all, some or none of for your custom routine. Those include the Bedtime Cue, which lets you know it's the time to start getting ready for bed (you designate this time); the Wind Down, or the sounds you'll fall asleep to; and the Noise Mask, the sounds that keep you asleep. If you wake up in the middle of the night, there's a Back To Sleep option too.
，更多细节参见夫子
Git packfiles use delta compression, storing only the diff when a 10MB file changes by one line, while the objects table stores each version in full. A file modified 100 times takes about 1GB in Postgres versus maybe 50MB in a packfile. Postgres does TOAST and compress large values, but that’s compressing individual objects in isolation, not delta-compressing across versions the way packfiles do, so the storage overhead is real. A delta-compression layer that periodically repacks objects within Postgres, or offloads large blobs to S3 the way LFS does, is a natural next step. For most repositories it still won’t matter since the median repo is small and disk is cheap, and GitHub’s Spokes system made a similar trade-off years ago, storing three full uncompressed copies of every repository across data centres because redundancy and operational simplicity beat storage efficiency even at hundreds of exabytes.
对首都北京的规划工作，明确提醒“规划科学是最大的效益，规划失误是最大的浪费，规划折腾是最大的忌讳”；
const cur = val; // 简化变量名，代表当前价格