XREADRead new entries from one or more streams, optionally blocking.
| 语法 | XREAD [COUNT count] [BLOCK milliseconds] STREAMS key [key ...] id [id ...] |
| 分组 | stream |
| 参数个数 | -4 |
| 起始版本 | 1.0.0 |
| 标志 | readonly, blocking |
| 复杂度 | O(S * (log N + M)) over S streams; '$' is O(1); the park is O(1) |
| Redis 兼容性 | differs: answers as valkey 9.1 does; Redis 8.10's unbalanced-streams error also names '+' as an accepted ID |