IDX.EXPLAINThe IDX.QUERY parse without the execution: kind, state, est_rows, and the plan line.
| 语法 | IDX.EXPLAIN name RANGE min max|EQ value|MATCH text|KNN vector|GROUPS [args ...] |
| 分组 | index |
| 参数个数 | -2 |
| 起始版本 | 3.0.0 |
| 标志 | readonly, extension |
| 复杂度 | The plan is parse-only, but est_rows costs the same live stats walk as IDX.LIST |
| Redis 兼容性 | kevy-only: nearest is FT.EXPLAIN, which returns a parsed query tree; ours returns kind, build state, estimated rows and a one-line plan |