IDX.COUNTCount index entries matching a range or equality predicate.
| 構文 | IDX.COUNT name RANGE min max | EQ value |
| グループ | index |
| 引数の数 | -4 |
| 導入バージョン | 3.0.0 |
| フラグ | readonly, extension |
| 計算量 | O(log N + matched) per shard — NOT an O(1) counter and not a B-tree rank query; it counts the matched range |
| Redis 互換性 | kevy-only: nearest is FT.SEARCH with LIMIT 0 0 |