On 10 Sep 2009, at 12:02am, Iker Arizmendi wrote: > The assumption being that a lock facility that can handle these issues > is needed by any concurrency scheme (MVCC, shadow pages, etc) and so > can > be thought about independently. Does the ability of a client-server > DB to > support multiple writers follow solely from the fact that it > centralizes > the lock bookkeeping and that it can easily detect death of its > children?
'Death of children' is an issue in some DBMS systems (like SQLite currently is), but not others. In particular, if you are using MVCC correctly, death of children hardly matters at all. All it means is that the DBMS engine will be using a little extra memory (and no extra processing power) until it decides that a child which hasn't done anything for an hour is probably not going to come back to life. Read up on MVCC. Read up on how to support ACID in a multiuser concurrent system. Neither allow a client to explicitly lock anything. Locks are handled by low-level processes inside the engine and last fractions of a second. Simon. _______________________________________________ sqlite-users mailing list sqlite-users@sqlite.org http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users
