Copies the value of a key to a new key.
COPY source destination [DB destination-db] [REPLACE]
This command copies the value stored at the source key to the destination key.
By default, the destination key is created in the logical database used by the connection. The DB option allows specifying an alternative logical database index for the destination key. The REPLACE option removes the destination key before copying the value to it.
The command returns zero when the source key does not exist or when the destination key already exists and the REPLACE option is not specified.
When the DB option is used, the caller must have ACL permission to access the specified destination database. See database permissions.
One of the following:
Integer reply: 1 if source was copied.
Integer reply: 0 if source was not copied when the destination key already exists.
O(N) worst case for collections, where N is the number of nested items. O(1) for string values.
@keyspace @slow @write
SET dolly "sheep"
COPY dolly clone
GET clone
DEL, DUMP, EXISTS, EXPIRE, EXPIREAT, EXPIRETIME, KEYS, MIGRATE, MOVE, OBJECT, OBJECT ENCODING, OBJECT FREQ, OBJECT HELP, OBJECT IDLETIME, OBJECT REFCOUNT, PERSIST, PEXPIRE, PEXPIREAT, PEXPIRETIME, PTTL, RANDOMKEY, RENAME, RENAMENX, RESTORE, SCAN, SORT, SORT_RO, TOUCH, TTL, TYPE, UNLINK, WAIT, WAITAOF.