IDX.COUNTCount index entries matching a range or equality predicate.
| Syntax | IDX.COUNT name RANGE min max | EQ value |
| Group | index |
| Arity | -4 |
| Since | 3.0.0 |
| Flags | readonly, extension |
| Complexity | O(log N + matched) per shard — NOT an O(1) counter and not a B-tree rank query; it counts the matched range |
| Redis compatibility | kevy-only: nearest is FT.SEARCH with LIMIT 0 0 |