LASTSAVE
Syntax
LASTSAVE
Time complexity: O(1)
Return the UNIX TIME of the last DB save executed with success.
A client may check if a BGSAVE command succeeded reading the LASTSAVE value,
then issuing a BGSAVE command and checking at regular intervals every N
seconds if LASTSAVE changed. Dragonfly considers the database saved successfully at startup.
Return
Integer reply: an UNIX time stamp.