SELECTSelect the logical database; kevy is single-DB and only accepts index 0.
| Syntax | SELECT index |
| Group | connection |
| Arity | 2 |
| Since | 1.0.0 |
| Flags | readonly |
| Complexity | O(1) |
| Redis compatibility | differs: kevy is single-DB — SELECT 0 replies OK and any other index is an error |