MD5 hashes can still collide. How does this implementation deal with hash collisions?
----- Original Message ----- From: "Alexey Pechnikov" <pechni...@mobigroup.ru> To: "General Discussion of SQLite Database" <sqlite-users@sqlite.org> Sent: Thursday, July 30, 2009 7:11 AM Subject: Re: [sqlite] Multi-master replication with updated Versioning extension > Hello! > > On Thursday 30 July 2009 17:25:15 P Kishor wrote: >> > I haven't looked at your work in depth, but I am interested in >> > this. I >> > have implemented a very simple versioning system with TRIGGERs >> > whereby >> > every change (INSERT, UPDATE, DELETE) in a column in a table is >> > stored >> > in a versions table along with its primary key, allowing me to go >> > back >> > and examine any version and roll back to it, if desired. > > Yes, the primary key field is good enough for master-slave > replication but not for > multi-master because each master has self sequence counter. And full > record > hash may be used for master-slave replication on tables without > primary keys. > > As table-independant way extension use ROWID field and md5 hash of > all fields. > So multi-master is possible with some restrictions such as > non-unique records > is denied. But may be ROWID + hash of record can help for this > situation too. > > Best regards, Alexey Pechnikov. > http://pechnikov.tel/ > _______________________________________________ > 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
