I'm not sure if you are looking to make a entry unique, or determine the order in which the entries occurred. In either case, be aware - time can go *backwards* on a system, especially if it is being syncd to an outside source such as with NTP.
Normally the 'jitter' is under a second, but exceptions do occur (including the one where the Sysadmin changes the system clock!). Note that a backward "jitter" could (conceivably) result in the same timestamp occurring twice. Also, depending on the resolution of the clock (which may vary depending on installation options) it may be possible for two entries to occur at the same 'time'. As a result, I've sworn off using the time for anything more than a logging label. I've had good success with the auto-increment approach. As for code to hide it, just set auto-incrementing up on a field in the schema, and there is no extra code involved. *** Doug F. -----Original Message----- From: sqlite-users-boun...@sqlite.org [mailto:sqlite-users-boun...@sqlite.org] On Behalf Of Alberto Simões Sent: Tuesday, September 15, 2009 4:38 AM To: General Discussion of SQLite Database Subject: [sqlite] Temporal SQLite database Dear SQLite users, I am preparing a temporal database. Basically, entries will have a compound key composed by the real key and some kind of time stamp. This is not complicated to do, but I would like to know if anybody did something similar and if: - used the number of non-leap seconds since whatever time the system considers to be the epoch, as time stamp - used an auto-increment value as the time-stamp, and adding the time stamp as an auxiliary column, - knows of any Perl module that hides this time management. Thanks for your ideas. ambs _______________________________________________ sqlite-users mailing list sqlite-users@sqlite.org http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users ______________________________________________________________________ This email has been scanned by the MessageLabs Email Security System. For more information please visit http://www.messagelabs.com/email ______________________________________________________________________ _______________________________________________ sqlite-users mailing list sqlite-users@sqlite.org http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users
