Answer: The most recent one.
Isn't it true that semi-accurate (sub-second) time-tagged transactions will generally keep 2 databases in sync? I've done that before with considerable success. You don't sync the fields...you sync the transactions. The presumption is that later transactions win regardless of intervening updates. Only problem is when times are too close (beyond your time-sync resolution) which requires human intervention...though in a user-driven system that should be nigh on to impossible to create. I do realize the complexity of keeping two database in sync....but transaction systems have been around for decades. Depends on your application. Michael D. Black Senior Scientist Advanced Analytics Directorate Advanced GEOINT Solutions Operating Unit Northrop Grumman Information Systems ________________________________ From: sqlite-users-boun...@sqlite.org [sqlite-users-boun...@sqlite.org] on behalf of Simon Slavin [slav...@bigfraud.org] Sent: Monday, June 11, 2012 5:03 PM To: General Discussion of SQLite Database Subject: EXT :Re: [sqlite] Features of SQLite question On 11 Jun 2012, at 10:14pm, Brent Shifley <brentshif...@yahoo.com> wrote: > I was wondering. If you had a SQLite database on two different iPads, then > had different changes applied to each database, is it possible to sync the > changes to each database? Suppose you have a list of contacts in a database and both copies have had one contact's phone number changed. Which 'new' phone number should appear in the merged copy ? If you are the writer of the application which accesses the databases, and you understand exactly how the application uses them, and how the users have been told to use the application, then you can build some synchrony features into your software. But writing a general solution -- something which will work on two copies of any SQL database -- is impossible. Not only for SQLite but for all relational databases no matter what DBMS is used. There are questions about how various changes should be handled which need either answering by a human or detailed information about how the application uses the database. It's not possible to write one program which can tell how to get the 'best' merging of the two copies without it. Simon. _______________________________________________ sqlite-users mailing list sqlite-users@sqlite.org http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users _______________________________________________ sqlite-users mailing list sqlite-users@sqlite.org http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users
